Series A Senior Notes 5.12 Percent Due 2033 Series A Senior Notes 5.12 Percent Due 2033 [Member] Series A Senior Notes 5.12 Percent Due 2033 Other accounts receivable, less allowance for doubtful accounts Accounts and Other Receivables, Net, Current 2026 Defined Benefit Plan, Expected Future Benefit Payment, Year Two Flow-through on fixed assets Effective Income Tax Rate Reconciliation, Nondeductible Expense, Depreciation, Amount Adjustments to reconcile net income to net cash provided by operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Low income rate assistance balancing accounts Low income rate assistance balancing accounts [Member] Low income rate assistance balancing accounts Repayments of long-term debt Repayments of Long-Term Debt Federal taxes on pretax income at statutory rate Effective Income Tax Rate Reconciliation at Federal Statutory Income Tax Rate, Amount Approved equity capital structure, percentage Public Utilities, Approved Equity Capital Structure, Percentage Thereafter Lessee, Operating Lease, Liability, to be Paid, after Year Five Regulatory asset wildfire mitigation plans WMP Regulatory Asset Wildfire Mitigation Plans WMP Regulatory Asset Wildfire Mitigation Plans WMP Maturities of operating lease liabilities Lessee, Operating Lease, Liability, to be Paid, Maturity [Table Text Block] Allowance for Doubtful Accounts Allowance for Doubtful Accounts -- None. No documentation exists for this element. -- Trading Symbol Trading Symbol Schedule of Regulatory Assets and Liabilities [Table] Schedule of Regulatory Assets and Liabilities [Table] A table of assets and liabilities that are created when regulatory agencies permit public utilities to defer certain costs and recognition of certain revenues that are included in rate-setting to the balance sheet. Long-Term Debt Long-Term Debt and Lease Obligation Non-NEOs Non-NEOs [Member] Tax benefits from exercise of stock-based awards Share-Based Payment Arrangement, Expense, Tax Benefit Total capitalization Total capitalization Capitalization, Long-Term Debt and Equity Dividends Paid Per Common Share (in USD per share) Common Stock, Dividends, Per Share, Declared Goodwill Goodwill and Intangible Assets, Goodwill, Policy [Policy Text Block] 2027 Defined Benefit Plan, Expected Future Benefit Payment, Year Three Impairment of Long-Lived Assets Asset Impairment Charges [Abstract] Incremental expansion of borrowing capacity Line of Credit Facility, Incremental Expansion of Borrowing Capacity Line of Credit Facility, Incremental Expansion of Borrowing Capacity Accounts receivable — customers Increase (Decrease) in Accounts Receivable Materials and Supplies Inventory, Policy [Policy Text Block] Non-Rule 10b5-1 Arrangement Adopted Non-Rule 10b5-1 Arrangement Adopted [Flag] Land Land [Member] Schedule of assumptions used to estimate fair value of each option grant on the grant date using the Black-Scholes option-pricing model Share-Based Compensation Arrangements by Share-Based Payment Award, Performance-Based Units, Vested and Expected to Vest [Table Text Block] Award Timing Disclosures [Line Items] Excess deferred tax amortization Income tax rate reconciliation, excess deferred tax amortization Income tax rate reconciliation, excess deferred tax amortization Accrued pension and other post-retirement benefits Increase (Decrease) in Obligation, Pension and Other Postretirement Benefits Ultimate health care cost for employees under age of 65 (as a percent) Defined Benefit Plan Ultimate Health Care Cost Trend Rate for Employees under Age Sixty Five The ultimate trend rate for health care costs for employees under age of sixty-five. Initial health care cost for employees under age of 65 (as a percent) Defined Benefit Plan Initial Health Care Cost Trend Rate for Employees under Age Sixty Five Represents the initial health care cost for employees under age of sixty-five. Operating Lease, Payments, Use Operating Lease, Payments, Use Portion at Fair Value Measurement [Member] Portion at Fair Value Measurement Portion at Fair Value Measurement [Member] Various third parties Various Third Parties [Member] Represents the information pertaining to various third parties. 2026 Purchase Obligation, to be Paid, Year Two Revenue from Contract with Customer [Abstract] Revenue from Contract with Customer [Abstract] Plan Name [Domain] Plan Name [Domain] Net changes in notes payable to banks Payments for Proceeds from Notes Payable to Bank The net change during the reporting period in amount of notes payable to banks, excluding mortgage notes, initially due beyond one year or beyond the operating cycle if longer. Other Deferred taxes and other assets Other Assets, Noncurrent Leases [Abstract] Leases [Abstract] Total intangible assets Finite-Lived Intangible Assets, Gross Regulatory assets Regulatory Asset Basis of Presentation: Basis of Presentation [Abstract] -- None. No documentation exists for this element. -- Net cash provided (used) Net Cash Provided by (Used in) Operating Activities Environmental Loss Contingency Statement OfFinancial Position Extensible Enumeration Not Disclosed Flag Environmental Loss Contingency Statement OfFinancial Position Extensible Enumeration Not Disclosed Flag Environmental Loss Contingency Statement OfFinancial Position Extensible Enumeration Not Disclosed Flag Cash Flows From Operating Activities: Net Cash Provided by (Used in) Operating Activities [Abstract] Accretion Asset Retirement Obligation, Accretion Expense Contracted services: Contracted Services [Member] Represents the contracted services unit of the entity. Award Timing Method Award Timing Method [Text Block] Net periodic pension costs Net periodic pension cost under accounting standards Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Trading Arrangements, by Individual Trading Arrangements, by Individual [Table] Entity Common Stock, Shares Outstanding (in shares) Entity Common Stock, Shares Outstanding Insider Trading Policies and Procedures [Line Items] Fair value of plan assets Defined Benefit Plan, Plan with Accumulated Benefit Obligation in Excess of Plan Assets, Plan Assets Adjustment to Compensation, Amount Adjustment to Compensation Amount Compensation Amount Outstanding Recovery Compensation Amount Remaining amount of commitment Purchase Commitment, Remaining Minimum Amount Committed Golden State Water Company and Bear Valley Electric Service, Inc. Golden State Water Company and Bear Valley Electric Service, Inc. [Member] Golden State Water Company and Bear Valley Electric Service, Inc. Number of States in which Entity Operates Number of States in which Entity Operates Aggregate Change in Present Value of Accumulated Benefit for All Pension Plans Reported in Summary Compensation Table Aggregate Change in Present Value of Accumulated Benefit for All Pension Plans Reported in Summary Compensation Table [Member] Entity Small Business Entity Small Business Less — accumulated depreciation Less — accumulated depreciation Public Utilities, Property, Plant and Equipment, Accumulated Depreciation Company Selected Measure Amount Company Selected Measure Amount Tabular List, Table Tabular List [Table Text Block] Level 3 Fair Value, Inputs, Level 3 [Member] Stock compensation plans Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] Patuxent River Utility Services LLC("PRUS") Patuxent River Utility Services LLC("PRUS") [Member] Patuxent River Utility Services LLC("PRUS") Accrued liability for the estimated additional cost to complete the clean-up at the site Accrual for Environmental Loss Contingencies Expected long-term return on plan assets Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-Term Rate of Return on Plan Assets Public Utility, Property, Plant and Equipment [Table] Public Utility, Property, Plant and Equipment [Table] Source of water supply Public Utilities Property Plant and Equipment Source of Water Supply Estimated Useful Life Represents the estimated useful life of property, plant and equipment (PPE) related to source of water supply owned by public utility. 2027 Long-Term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Three Net loss (gain) Net loss Defined Benefit Plan Amounts Recognized in Regulatory Asset, Liability Net Gains (Losses) Represents the net gains and losses recognized in regulatory asset (liability). Impairment of Long-Lived Assets Impairment or Disposal of Long-Lived Assets, Policy [Policy Text Block] Advances for construction Advances For Construction Advances For Construction Credit Facility [Domain] Credit Facility [Domain] Schedule of Pension Plan's funded status and amounts recognized in balance sheets and the components of net pension cost and accrued post-retirement liability Schedule of Plans Funded Status and Amount Recognized in Balance Sheets Components of Net Pension Cost Accrued Post Retirement Liability and Assumptions [Table Text Block] Tabular disclosure of pension plan's funded status and amounts recognized in the entity's balance sheets, the components of net pension cost and accrued post-retirement liability, estimated amounts that will be amortized in next fiscal year and weighted average assumptions to calculated benefit obligations. Property and other taxes Taxes, Miscellaneous Accounts and Financing Receivables [Table] Accounts and Financing Receivables [Table] Net changes in intercompany borrowings Payments for Proceeds from Related Party Debt This element represents the net change during the reporting period in amount of payments for proceeds from related party debt. Balance at beginning of year Balance at end of year Total allowance for doubtful accounts Accounts Receivable, Allowance for Credit Loss Other Regulatory Liabilities Other Regulatory Liabilities [Member] Other Regulatory Liabilities Other Payment, Tax Withholding, Share-Based Payment Arrangement Dividend Reinvestment Plan Common Stock Capital Shares Reserved for Future Issuance Dividend Reinvestment Plan Common Stock Capital Shares Reserved for Future Issuance Represents the number of common shares authorized but unissued under the Dividend Reinvestment Plan. Performance criteria adjustment (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Performance Criteria Adjustment, Weighted Average Grant Date Fair Value Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Performance Criteria Adjustment, Weighted Average Grant Date Fair Value Fixed income fund Fixed income securities Fixed Income Funds [Member] Entity Information [Line Items] Entity Information [Line Items] Nonqualified stock options Stock options Share-Based Payment Arrangement, Option [Member] BVES Bear Valley Electric Service, Inc. [Member] Bear Valley Electric Service, Inc. Depreciation Depreciation Pension Benefits Pension Benefits Pension Plan [Member] Balance in Rabbi Trust Defined Benefit Plan Fair Value of Plan Assets Subject to Claims of Creditors Represents the fair value of plan assets subject to claims of creditors. Relief funding Relief funding COVID relief funds through the Extended Arrearage Program Award Type [Axis] Award Type [Axis] Accumulated deferred income taxes - net Deferred Tax Liabilities, Net Basic Earnings Per Common Share Earnings Per Share, Basic [Abstract] Number of Plant Sites Number of Plant Sites Number of plant sites that contained an underground storage tank Regulatory Rate Case Filings Requested Authorization For Debt And Equity Issuance Amount Regulatory Rate Case Filings Requested Authorization For Debt And Equity Issuance Amount Regulatory Rate Case Filings Requested Authorization For Debt And Equity Issuance Amount Public Utility Property, Plant, and Equipment Public Utility Property, Plant, and Equipment [Table Text Block] Net utility plant Net utility plant Total utility plant Property, Plant and Equipment, Net ICFR Auditor Attestation Flag ICFR Auditor Attestation Flag Water revenue adjustment mechanism, net of the modified cost balancing account Water Revenue Adjustment Mechanism Net of Modified Cost Balancing Account [Member] Represents the regulatory assets arising from water revenue adjustment mechanism, net of modified cost balancing account. Purchase power contract derivative at fair value (Note 5) Energy Marketing Contract Liabilities, Current Deferred taxes and other liabilities Accrued Income Taxes and other Liabilities Noncurrent The noncurrent portion of tax liabilities and also includes the aggregate carrying amount, as of the balance sheet date, of noncurrent obligations not separately disclosed in the balance sheet. Bank Debt Bank Debt Disclosure [Text Block] Entire disclosure of bank debts which includes bank commitments, letter of credits, etc. of the reporting entity. Common Stock, Par or Stated Value Per Share Common Stock, Par or Stated Value Per Share Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-Based Compensation Arrangements by Share-Based Payment Award [Table] Weighted Average Amortization Period (in years) Acquired Finite-Lived Intangible Assets, Weighted Average Useful Life Revolving Credit Facility Revolving Credit Facility [Member] Initial price contract value and subject to annual economic price adjustments Initial price contract value and subject to annual economic price adjustments Initial price contract value and subject to annual economic price adjustments Expiration Date Trading Arrangement Expiration Date Cash Flows From Investing Activities: Net Cash Provided by (Used in) Investing Activities [Abstract] Other Assets Other Assets [Abstract] Operating lease liabilities Less: current obligations Operating Lease, Liability, Current Total Shareholder Return Amount Total Shareholder Return Amount Reconciliations of the effective tax rates to the federal statutory rate Income Tax Expense (Benefit), Effective Income Tax Rate Reconciliation, Amount [Abstract] Advances for Construction and Contributions in aid of Constructions Customer Advances or Deposits, Noncurrent [Abstract] Equity Awards Adjustments, Footnote Equity Awards Adjustments, Footnote [Text Block] Asset Retirement Obligation, Liabilities Incurred Asset Retirement Obligation, Liabilities Incurred Water Water [Member] Materials and supplies Inventory, Raw Materials and Supplies, Gross Provision for doubtful accounts charged to expense and accounts written off, net of recoveries Allowance for Doubtful Accounts Receivable [Line Items] -- None. No documentation exists for this element. -- Total utility plant, at cost Total utility plant, at cost Property, Plant and Equipment, Gross Retirement Plan Name [Axis] Retirement Plan Name [Axis] Debt Instrument [Line Items] Debt Instrument [Line Items] Debt Instrument [Line Items] Derivative instrument memorandum account (Note 5) Gain (Loss) on Derivative Instruments [Member] Accounting Policies [Table] Accounting Policies [Table] Schedule detailing accounting policies of the entity. Named Executive Officers, Footnote Named Executive Officers, Footnote [Text Block] Weighted Average Exercise Price Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract] Basis of Accounting, Policy Basis of Accounting, Policy [Policy Text Block] Weighted Average Number of Diluted Shares (in shares) Weighted Average Number of Diluted Shares (in shares) Weighted Average Number of Diluted Common Shares Outstanding (in shares) Weighted Average Number of Shares Outstanding, Diluted Union plan Other Postretirement Benefit Union Plan Defined Benefit [Member] Represents information pertaining to the union plan covered under the post-retirement medical plans. Performance criteria adjustment (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Performance Criteria Adjustment Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Performance Criteria Adjustment Condensed balance sheet Condensed financial statements Condensed Financial Statements, Captions [Line Items] MNPI Disclosure Timed for Compensation Value MNPI Disclosure Timed for Compensation Value [Flag] 2025 Purchase Obligation, to be Paid, Year One Common shareholder’s equity Beginning Balance Ending Balance Common shareholder’s equity Equity, Attributable to Parent Dividend Limitations Disclosure [Table] Dividend Limitations Disclosure [Table] Table providing information pertaining to dividend limitations. Deferred tax assets Deferred Tax Assets, Gross Power purchased for resale Utilities Operating Expense, Purchased Power Construction work in progress Construction in Progress, Gross Loss before equity in earnings of subsidiaries and income taxes Operating Income (Loss) Including Other Income The net result for the period of deducting operating expenses from operating revenues and other income. Concentration Risk Type [Domain] Concentration Risk Type [Domain] Category of Item Purchased [Axis] Category of Item Purchased [Axis] Employer contribution to the plan Defined Contribution Plan, Cost 2029 Long-Term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Five 4.548% note due 2032 Notes Payable 4.548 Percent Due 2032 [Member] Notes Payable 4.548 Percent Due 2032 Utility Plant [Domain] Utility Plant [Domain] Document Fiscal Period Focus Document Fiscal Period Focus Number of credit facilities Number of credit facilities Number of credit facilities All Executive Categories All Executive Categories [Member] Stock-based compensation (in shares) Incremental Common Shares Attributable to Dilutive Effect of Share-Based Payment Arrangements Equity securities Equity Securities [Member] 2026 Finite-Lived Intangible Asset, Expected Amortization, Year Two Changed Peer Group, Footnote Changed Peer Group, Footnote [Text Block] Property installed by developers and conveyed Contribution of Property Add: Addition [Abstract] -- None. No documentation exists for this element. -- Assets Assets [Abstract] 2000 and 2008 Employee Plans Employee Plans 2016 and 2003 and 2013 directors' plan [Member] Represents information pertaining to the 2016 Employee Plans, 2003 and 2013 directors plans Retirement Plan Type [Domain] Retirement Plan Type [Domain] Document Type Document Type Interest Rate at the end of the period (as a percent) Debt Instrument, Interest Rate, Effective Percentage Derivative Contract Type [Domain] Derivative Contract [Domain] Allowance for doubtful accounts receivable charge offs net of recoveries Allowance for Doubtful Accounts Receivable Charge Offs Net of Recoveries Represents the amount of direct write-downs of receivables, net of recoveries, charged against the allowance for doubtful accounts. Regulatory Matters Schedule of Regulatory Assets and Liabilities [Text Block] Actuarial (gain) loss Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss) Maturity period of investments Investments Maturity Period Represents the maturity period of investments. Schedule of reporting segments information Schedule of Segment Reporting Information, by Segment [Table Text Block] Electric Renewable Energy Credit Purchase Commitments Electric Renewable Energy Credit Purchase Commitments [Member] Electric Renewable Energy Credit Purchase Commitments Schedule of provision for doubtful accounts charged to expense and accounts written off, net of recoveries Allowance for Doubtful Accounts Receivable [Table Text Block] Tabular disclosure of the allowance for doubtful accounts of the entity. Defined Benefit Plan [Table] Defined Benefit Plan [Table] Water treatment Water Treatment Equipment [Member] Represents information pertaining to the water treatment equipment. Contract with Customer, Contract Asset, Contract Liability, and Receivable [Table Text Block] Contract with Customer, Contract Asset, Contract Liability, and Receivable [Table Text Block] Schedule of estimated future consolidated amortization expenses related to intangible assets Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block] Sales Sales [Member] Minimum age for eligibility under the Pension Plan Defined Benefit Plan Minimum Age for Eligibility Represents the minimum age required by the employees to be eligible to participate in the plan. Maximum Maximum Maximum [Member] AWR Parent Company Parent Company [Member] Eligibility for employer matching contributions, period of service Defined Contribution Plan Eligible Period of Service for Matching Contribution The period of service required in order to be eligible for the employer's matching contributions. Equity Valuation Assumption Difference, Footnote Equity Valuation Assumption Difference, Footnote [Text Block] Intangible assets, net of amortization Finite-Lived Intangible Assets, Net Accounts payable Accounts Payable, Current Water purchased Utilities Operating Expense, Water Purchased Utilities Operating Expense, Water Purchased Related Party Transaction, Amounts of Transaction Related Party Transaction, Amounts of Transaction Electric Regulated Operating Revenue, Electric, Non-Nuclear Lease, Cost Lease, Cost Cost of debt, percentage Public Utilities, Approved Cost of Debt , Percentage Public Utilities, Approved Cost of Debt , Percentage Statistical Measurement [Axis] Statistical Measurement [Axis] 6.81% notes due 2028 Notes Payable 6.81 Percent Due 2028 [Member] Represents the 6.81 percent notes, due in 2028. Non-Rule 10b5-1 Arrangement Terminated Non-Rule 10b5-1 Arrangement Terminated [Flag] Income before income taxes Income before income taxes Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Non-PEO NEO Average Total Compensation Amount Non-PEO NEO Average Total Compensation Amount U.S. large cap funds U.S. equity securities U S Large Cap Stocks [Member] Represents information pertaining to the United States large cap stocks. Net liability (asset) recognized Defined Benefit Plan, Amounts Recognized in Regulatory Assets (Liabilities), Net Defined Benefit Plan, Amounts Recognized in Regulatory Assets (Liabilities), Net Fixed assets Deferred Tax Liabilities, Property, Plant and Equipment Name Outstanding Recovery, Individual Name Water planning studies Water Planning Studies [Member] Represents information pertaining to the water planning studies. Disaggregation of Revenue [Line Items] Disaggregation of Revenue [Line Items] Title and Position [Axis] Title and Position [Axis] Franchisor Franchisor [Member] Net change in cash and cash equivalents Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect Conservation programs Conservation [Member] Represents information pertaining to the conservation. Net changes in notes payable to banks Proceeds from (Repayments of) Notes Payable Award Timing Predetermined Award Timing Predetermined [Flag] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Amortization of prior service cost (credit) Defined Benefit Plan, Amortization of Prior Service Cost (Credit) Long-Term Debt Long-Term Debt [Text Block] Earnings Per Share, Diluted Fully Diluted Earnings per Common Share (in USD per share) Earnings Per Share, Diluted Number of renewable energy credits that would be purchased Purchased Renewable Energy Credits Number Represents the number of renewable energy credits that would be purchased over a contractual period of time. Period within which Expected Additional Revenue Collection is Recorded Subject to Undercollection of Revenue Period within which Expected Additional Revenue Collection is Recorded Subject to Undercollection of Revenue Represents the number of months within which expected additional revenue collection is recorded when the difference between volumetric revenues as authorized by the CPUC for metered accounts (volumetric revenues) and the actual volumetric revenues recovered in customer rates results in an undercollection of revenues. Counterparty Name [Domain] Counterparty Name [Domain] Other Other Products and Services [Member] Other Products and Services [Member] Contract liabilities Increase (Decrease) in Contract with Customer, Liability Total current tax expense Current Income Tax Expense (Benefit) Regulatory Liability [Domain] Regulatory Liability [Domain] Restatement does not require Recovery Restatement Does Not Require Recovery [Text Block] Retroactive water revenues impact as a result of a proposed decision Retroactive water revenues impact as a result of a proposed decision Retroactive water revenues impact as a result of a proposed decision for the full year of 2022 Ratio of Indebtedness to EBITDA Ratio of Indebtedness to EBITDA Ratio of Indebtedness to EBITDA Retirement Benefits [Abstract] Retirement Benefits [Abstract] Percentage of participant's eligible pay contributed to the plan by the employer Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay Regulatory asset not accruing carrying costs Regulatory Asset Not Accruing Carrying Costs Represents the regulatory asset not accruing carrying costs as of the balance sheet date. Less: impact from participating securities Participating Securities, Distributed and Undistributed Earnings (Loss), Basic Statement of Financial Position [Abstract] Statement of Financial Position [Abstract] Commercial paper, term Investment Term Represents the term associated with a fixed-term security. Income tax expense Total income tax expense operations Income tax benefit Income Tax Expense (Benefit) Interest cost Defined Benefit Plan, Interest Cost Other Income and Expenses Nonoperating Income (Expense) [Abstract] Components of Net Periodic Benefits Cost: Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract] Expected recognition period for unrecognized compensation cost Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition Revenue from contract with customers Revenue from Contract with Customer, Excluding Assessed Tax Net cash provided (used) Net Cash Provided by (Used in) Investing Activities Contract assets (Note 2) Contract with Customer, Asset, before Allowance for Credit Loss, Noncurrent Other plant Public Utilities, Property, Plant and Equipment, Other Property Plant and Equipment, Useful Life All Adjustments to Compensation All Adjustments to Compensation [Member] Accrued employee expenses Employee-related Liabilities, Current Prepayments and other assets Increase (Decrease) in Prepaid Expense and Other Assets Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Disclosure [Abstract] Legal Entity [Axis] Legal Entity [Axis] 2026 Long-Term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Two Regulatory Asset [Axis] Regulatory Asset [Axis] Estimated useful lives of utility plant, as authorized by the CPUC Public Utilities, Property, Plant and Equipment, Net [Abstract] Purchase power contract Commodity Contract [Member] Revised price contract value after an inventory adjustment Revised price contract value after an inventory adjustment Revised price contract value after an inventory adjustment Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period Ultimate health care cost for employees of age 65 and over (as a percent) Defined Benefit Plan Ultimate Health Care Cost Trend Rate for Employees of Age Sixty Five and over The ultimate trend rate for health care costs for employees of age sixty-five and over. 5.12% notes due 2033 Notes Payable 5.12 Percent Due 2033 [Member] Notes Payable 5.12 Percent Due 2033 Assumptions used to estimate fair value of each option grant on the grant date using the Black-Scholes option-pricing model Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions and Methodology [Abstract] Source of water supply Source of Water Supply [Member] Represents information pertaining to source of water supply. Long-term Debt, Type [Domain] Long-Term Debt, Type [Domain] Entity Address, State or Province Entity Address, State or Province Derivative Instruments and Hedging Activities Disclosure [Abstract] Derivative Instruments and Hedging Activities Disclosure [Abstract] Utility plant before construction work in progress Property Plant and Equipment before Construction Work in Progress Tangible assets that are held by an entity for use in the production or supply of goods and services, for rental to others, or for administrative purposes and that are expected to provide economic benefit for more than one year; net of accumulated depreciation but before construction work in progress. Examples include land, buildings, machinery and equipment, and other types of furniture and equipment including, but not limited to, office equipment, furniture and fixtures, and computer equipment and software. Erroneous Compensation Analysis Erroneous Compensation Analysis [Text Block] Normal retirement benefit (as a percent) Defined Benefit Plan Retirement Benefit Percentage Represents the percentage of normal retirement benefit. CPUC-approved surcharges (cost-recovery activities) Surcharges (Cost-recovery Activities) [Member] Surcharges (Cost-recovery Activities) [Member] Defined Benefit Plan, Plan Assets, Category [Domain] Defined Benefit Plan, Plan Assets, Category [Domain] Defined Benefit Plan Disclosure [Line Items] Employee benefit plans Defined Benefit Plan Disclosure [Line Items] Military Privatization Accounts, Notes, Loans and Financing Receivable [Line Items] Allowance for Doubtful Accounts Allowance for Doubtful Accounts Disclosure [Text Block] Entire disclosure of allowance on doubtful accounts of the reporting entity. Restricted share units at the beginning of the period (in dollars per share) Restricted share units at the end of the period (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value Schedule of regulatory assets, less regulatory liabilities in the consolidated balance sheets for continuing operations Schedule of Regulatory Assets Liabilities [Table Text Block] Tabular disclosure of regulatory assets, less regulatory liabilities, included in consolidated balance sheets for continuing operations. Capitalization and Liabilities Liabilities and Capitalization Liabilities and Equity [Abstract] Derivatives Instruments Derivatives and Fair Value [Text Block] Approved debt capital structure, percentage Public Utilities, Approved Debt Capital Structure, Percentage Risks and Uncertainties [Abstract] Risks and Uncertainties [Abstract] Restatement Determination Date Restatement Determination Date Fair Value Estimate of Fair Value Measurement [Member] Allowance for doubtful accounts related to accounts receivable-customer Allowance for Doubtful Accounts Related to Receivable from Customer Represents the provision for doubtful accounts related to accounts receivable from customers. Operating expenses and other expenses Operating Expenses and Other Expenses Operating Expenses and Other Expenses Pay vs Performance Disclosure Pay vs Performance Disclosure [Table] SCHEDULE I - CONDENSED FINANCIAL INFORMATION OF PARENT Condensed Financial Information of Parent Company Only Disclosure [Text Block] Taxes and Interest Paid: Taxes and Interest Paid [Abstract] -- None. No documentation exists for this element. -- Number of contracts Number of contracts Number of contracts with 15-year contract with the U.S. government. Operating lease right-of-use assets Operating Lease, Right-of-Use Asset Erroneously Awarded Compensation Recovery Erroneously Awarded Compensation Recovery [Table] Modified Cost Balancing Account Modified Cost Balancing Account [Member] Represents the regulatory assets arising from modified cost balancing account. Condensed Financial Information Disclosure [Abstract] Condensed Financial Information Disclosure [Abstract] Line of credit facility, accordion feature, increase limit Line of Credit Facility, Accordion Feature, Increase Limit Line of Credit Facility, Accordion Feature, Increase Limit Fair Value, Liabilities Measured on Recurring Basis Fair Value, Liabilities Measured on Recurring Basis [Table Text Block] 2.90% notes due 2040 Notes Payable 2.90 Percent Due 2040 [Member] Notes Payable 2.90 Percent Due 2040 Earnings Per Share / Capital Stock Earnings Per Share [Text Block] Purchase Commitment, Excluding Long-term Commitment [Domain] Purchase Commitment, Excluding Long-Term Commitment [Domain] Subsequent Event Subsequent Event [Member] Issuance of Common Shares under stock-based compensation plans ( in shares) Stock Issued During Period, Value, Stock Options Exercised Changes in plan assets and benefit obligations recognized in regulatory assets (liabilities): Defined Benefit Plan Change in Plan Assets and Benefit Obligations Recognized in Regulatory Assets [Roll Forward] -- None. No documentation exists for this element. -- Granted (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value U.S. small/mid cap funds U S Small Cap Stocks [Member] Represents information pertaining to the United States small cap stocks. Additional disclosure Earnings Per Share, Basic, Other Disclosure [Abstract] Peer Group Issuers, Footnote Peer Group Issuers, Footnote [Text Block] Taxes on income Income Tax Disclosure [Line Items] -- None. No documentation exists for this element. -- Segments [Domain] Segments [Domain] Renewables Portfolio Standard (Bundled Product) Renewables Portfolio Standard (Bundled Product) [Member] Renewables Portfolio Standard (Bundled Product) Commitments Commitments Disclosure [Text Block] 2003 and 2013 Directors plans 2003 and 2013 Directors plans [Member] 2003 and 2013 Directors plans [Member] International funds International Funds [Member] Represents information pertaining to international funds. Regulatory liabilities not accruing carrying costs Regulatory Liabilities Not Accruing Carrying Costs Regulatory Liabilities Not Accruing Carrying Costs PEO PEO [Member] Number of stock incentive plans Number of Stock Incentive Plans Represents the number of stock incentive plans of the entity. Name Trading Arrangement, Individual Name Overfunded/(underfunded) amount recognized Net amount recognized as accrued pension cost Defined Benefit Plan, Funded (Unfunded) Status of Plan Entity Public Float Entity Public Float Debt issuance costs, line of credit arrangements, gross Debt Issuance Costs, Line of Credit Arrangements, Gross Public Utilities, Regulatory Proceeding [Domain] Public Utilities, Regulatory Proceeding [Domain] Equity in earnings of subsidiaries Income (Loss) from Equity Method Investments Water Supply Water Purchase Commitments [Member] Represents activity related to commitments to purchase water or water rights. Projected benefit obligation at beginning of year Projected benefit obligation at end of year Projected benefit obligation Defined Benefit Plan, Benefit Obligation Awards Close in Time to MNPI Disclosures, Table Awards Close in Time to MNPI Disclosures [Table Text Block] Maximum Amount Outstanding Short-Term Debt, Maximum Amount Outstanding During Period Prior Year End Fair Value of Equity Awards Granted in Any Prior Year that Fail to Meet Applicable Vesting Conditions During Covered Year Prior Year End Fair Value of Equity Awards Granted in Any Prior Year that Fail to Meet Applicable Vesting Conditions During Covered Year [Member] Nature of Operations: Nature of Operations [Abstract] -- None. No documentation exists for this element. -- Bank Debt Bank Debt -- None. No documentation exists for this element. -- Aggregate Erroneous Compensation Amount Aggregate Erroneous Compensation Amount Local Phone Number Local Phone Number Water: Water Water Service Utility Operations [Member] Represents the water service utility operations of the entity. Aggregate Erroneous Compensation Not Yet Determined Aggregate Erroneous Compensation Not Yet Determined [Text Block] Increase in investment of subsidiary Payments to Acquire Interest in Subsidiaries and Affiliates Total Finite Lived Intangible Assets Estimated Future Amortization Expense Represents the amount of amortization expense expected to be recorded in the succeeding five fiscal years for finite-lived intangible assets. Change in Accounting Estimate by Type [Axis] Change in Accounting Estimate by Type [Axis] Additional disclosure Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Additional Disclosures [Abstract] Changes in assets and liabilities: Increase (Decrease) in Operating Capital [Abstract] Groundwater production assessment Groundwater Production Assessment This element represents the aggregate expenses on groundwater production assessment. PEO Total Compensation Amount PEO Total Compensation Amount Changes in the fair value of the derivative Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] Other Credits Liabilities, Other than Long-Term Debt, Noncurrent [Abstract] Accrued interest Interest Payable, Current Defined Benefit Plan, Plan Assets, Category [Axis] Defined Benefit Plan, Plan Assets, Category [Axis] Term for the cost of capital proceeding Term for the cost of capital proceeding Term for the cost of capital proceeding Debt Disclosure [Abstract] Debt Disclosure [Abstract] Common Stock Common Stock [Member] Schedule of Condensed Financial Statements [Table] Condensed Financial Statements [Table] Forgone Recovery due to Expense of Enforcement, Amount Forgone Recovery due to Expense of Enforcement, Amount Depreciation on transportation equipment Public Utilities Property Plant and Equipment Depreciation on Transportation Equipment The amount of expense recognized in the current period that reflects the allocation of the cost of transportation equipment over the assets' useful lives. Incremental vegetation management costs Incremental vegetation management costs Incremental vegetation management costs- Regulatory asset Aggregate composite rate for depreciation (as a percent) Public Utilities, Property, Plant and Equipment, Disclosure of Composite Depreciation Rate for Plants in Service Segment Reporting [Abstract] Segment Reporting [Abstract] Entity Central Index Key Entity Central Index Key Goodwill arose from acquisition of subcontractor's business Goodwill Acquired in Prior Period The aggregate amount of goodwill acquired in the prior period. Loans (made to)/repaid from, wholly-owned subsidiaries Proceeds from Collection of (Payments to Fund) Long-Term Loans to Related Parties Other segment item, income (expense) Segment Reporting, Other Segment Item, Amount Goodwill Goodwill [Abstract] -- None. No documentation exists for this element. -- Non-PEO NEO Average Compensation Actually Paid Amount Non-PEO NEO Average Compensation Actually Paid Amount Balancing and memorandum accounts (non-flow-through) Deferred Tax Liabilities Balancing and Memorandum Accounts Represents the amount of deferred tax liability attributable to taxable temporary differences from balancing and memorandum accounts. Award Timing, How MNPI Considered Award Timing, How MNPI Considered [Text Block] Note payable to bank, noncurrent Notes payable to bank Notes Payable to Bank, Noncurrent Business Segments Segment Reporting Disclosure [Text Block] Dividend equivalent rights on stock-based awards Dividends Equivalent Rights on Share Based Compensation Net of Tax This element represents dividend equivalent rights on stock based awards, net of tax effect. Sale of Stock, Maximum Consideration On Transaction Sale of Stock, Maximum Consideration On Transaction Sale of Stock, Maximum Consideration On Transaction Unrealized (losses) gains on purchase power contracts Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Earnings Stock-based compensation, net of taxes paid from shares withheld from employees related to net share settlements APIC, Share-Based Payment Arrangement, Increase for Cost Recognition Restricted Stock [Member] Restricted Stock [Member] Debt due Feb 2030 Private -placement notes due Feb 12, 2030 at coupon rate 6.12% [Member] Private -placement notes due Feb 12, 2030 at coupon rate 6.12% Measurement Basis [Axis] Measurement Basis [Axis] Title Trading Arrangement, Individual Title Consolidated Entities [Axis] Consolidated Entities [Axis] Pensions and other post-retirement obligations (Note 12) Pension Costs and Other Postretirement Benefit Costs [Member] Represents the regulatory assets arising from pensions and other post-retirement obligations. Unbilled receivable Increase (Decrease) In Unbilled Contracts Receivables Increase (Decrease) In Unbilled Contracts Receivables Unrecognized Tax Benefits Unrecognized Tax Benefits Allowance for Doubtful Accounts Receivable [Table] Allowance for Doubtful Accounts Receivable [Table] Information about valuation allowance for receivables that are expected to be uncollectible. City Area Code City Area Code Current Liabilities Liabilities, Current [Abstract] Auditor Location Auditor Location 5.50% notes due 2027 Notes Payable 5.50 Percent Due 2027 [Member] Notes Payable 5.50 Percent Due 2027 Insider Trading Policies and Procedures Not Adopted Insider Trading Policies and Procedures Not Adopted [Text Block] Dividends Payable [Table] Dividends Payable [Table] Pumping Water Pumping Equipment [Member] Represents information pertaining to the water pumping equipment. Pension and Other Post Retirement Obligations [Axis] Pension and Other Post Retirement Obligations [Axis] Information by type of pension and post retirement obligations. Long-term debt Long-Term Debt, Excluding Current Maturities Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Weighted Average Grant-Date Value Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract] Number of customers served Number of Customers Represents the number of customers who are served by the entity. Subsequent Event Type [Axis] Subsequent Event Type [Axis] 7.875% notes due 2030 Notes Payable 7.875 Percent Due 2030 [Member] Represents the 7.875 percent notes, due in 2030. Earnings Per Share [Abstract] Earnings Per Share [Abstract] Recovery period Regulatory Asset Recovery Periods Represents the recovery periods of the surcharge billed to the customers. Pension and Other Post Retirement Obligations [Domain] Pension and Other Post Retirement Obligations [Domain] The name of the pension and post retirement obligations. 6.59% notes due 2029 Notes Payable 6.59 Percent Due 2029 [Member] Represents the 6.59 percent notes, due in 2029. Retained earnings Retained Earnings (Accumulated Deficit) Defined benefit plan number of highest consecutive years average earnings used in computing retirement benefit Defined Benefit Plan Number of Highest Consecutive Years Average Earnings Used in Computing Retirement Benefit Represents the number of highest consecutive years' average earnings used in computing the retirement benefit. Other Property and Investments Property, Plant and Equipment, Other, Net [Abstract] Total funded debt ratio Debt Instrument Covenant Funded Debt Ratio Represents the funded debt ratio required to be maintained for debt instrument. Supplemental Cash Flow Elements [Abstract] Supplemental Cash Flow Elements [Abstract] Administrative and general General and Administrative Expense Deferred income taxes and investment tax credits Deferred Income Taxes and Tax Credits Aggregate Available Trading Arrangement, Securities Aggregate Available Amount Schedule of Short-term Debt Schedule of Short-Term Debt [Table Text Block] Equity Awards Adjustments Equity Awards Adjustments [Member] Sale of Stock, Agreement Term Sale of Stock, Agreement Term Sale of Stock, Agreement Term Total lease obligations Operating Lease, Liability Underlying Securities Award Underlying Securities Amount Performance awards Performance Shares [Member] Regulatory assets — current Regulatory Asset, Current Unsecured Private Placement Notes Unsecured Private Placement Notes [Member] Unsecured Private Placement Notes Weighted-average assumptions used to determine net periodic cost: Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract] Regulatory adjustment increase (decrease) Regulatory adjustment - deferred Regulatory adjustment Increase (Decrease) in Other Regulatory Assets Amendment Flag Amendment Flag Carrying Amount Reported Value Measurement [Member] Stock Appreciation Rights (SARs) Stock Appreciation Rights (SARs) [Member] Supplemental Cash Flow Information Cash Flow, Supplemental Disclosures [Text Block] Actual return on plan assets Defined Benefit Plan, Plan Assets, Increase (Decrease) for Actual Return (Loss) Sale of Stock, Number of Shares Issued in Transaction Sale of Stock, Number of Shares Issued in Transaction Debt Issuance Costs, Net Debt Issuance Costs, Net Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Schedule of pension and post-retirement plan target asset allocations Schedule of Target Allocation of Plan Assets [Table Text Block] Tabular disclosure of pension and post-retirement plan target asset allocations. Recovery of Erroneously Awarded Compensation Disclosure [Line Items] Total expense recognized, before surcharges and allocation to overhead pool Defined Benefit Plan, Net Periodic Benefit Cost before Allocation to Overhead Pool The total amount of net periodic benefit cost for defined benefit plans during the period, before allocation to overhead pool. Debt Instrument, Face Amount Debt Instrument, Face Amount 6.00% notes due 2041 Notes Payable 6 Percent Due 2041 [Member] Represents the 6 percent notes, due in 2041. Utility Plant and Intangible Assets Utility Plant and Intangible Assets -- None. No documentation exists for this element. -- American Recovery and Reinvestment Act Obligation due 2033 American Recovery and Reinvestment Act Obligation Due 2033 [Member] Represents activity related to American Recovery and Reinvestment Act Obligation, due in 2033. Entity Address, Postal Zip Code Entity Address, Postal Zip Code Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis with Unobservable Inputs Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis with Unobservable Inputs Unbilled revenue, receivable from U.S government Unbilled Receivables, Not Billable Cash and cash equivalents Cash and cash equivalents, beginning of period Cash and cash equivalents, end of year Cash and Cash Equivalents, at Carrying Value Other investing activities Payments for (Proceeds from) Other Investing Activities Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested [Member] Auditor Name Auditor Name Deduct: Deduction [Abstract] -- None. No documentation exists for this element. -- Forfeited (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value Current Current Income Tax Expense (Benefit), Continuing Operations [Abstract] Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested [Member] Number of Options Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding [Roll Forward] Water treatment Public Utilities Property Plant and Equipment Water Treatment Estimated Useful Life Represents the estimated useful life of property, plant and equipment (PPE) related to water treatment owned by public utility. Depreciation and amortization Depreciation, Depletion and Amortization, Nonproduction Fair Value Measurement [Domain] Fair Value Measurement [Domain] Accounts payable Increase (Decrease) in Accounts Payable Water and water service rights Water and Water Service Rights [Member] Represents information pertaining to the water and water service rights. Adjustment To PEO Compensation, Footnote Adjustment To PEO Compensation, Footnote [Text Block] Schedule of components of net periodic pension and post-retirement benefits cost, before allocation to the overhead pool Schedule of Net Benefit Costs and Assumptions [Table Text Block] Tabular disclosure of the components of net benefit costs for pension plans and/or other employee benefit plans including service cost, interest cost, expected return on plan assets, gain (loss), prior service cost or credit, transition asset or obligation, and gain (loss) recognized due to settlements or curtailments and assumptions used to determine for pension plans and/or other employee benefit plans net benefit cost, including assumed discount rates, rate increase in compensation increase, and expected long-term rates of return on plan assets. Total income available to common shareholders Net Income (Loss) Available to Common Stockholders, Basic Generation Electric Generation Equipment [Member] Compensation Actually Paid vs. Other Measure Compensation Actually Paid vs. Other Measure [Text Block] Vesting Date Fair Value of Equity Awards Granted and Vested in Covered Year Vesting Date Fair Value of Equity Awards Granted and Vested in Covered Year [Member] 5.50% notes due 2026 Notes Payable 5.5 Percent Due 2026 [Member] Represents the 5.5 percent notes, due in 2026. Projected benefit obligation Defined Benefit Plan, Pension Plan with Accumulated Benefit Obligation in Excess of Plan Assets, Projected Benefit Obligation Total Assets Assets Intercompany receivable/payable Increase (Decrease) in Related Party Receivable Payable, Current The increase (decrease) during the reporting period of related party receivables/payables which are due within one year or one business cycle. ASUS construction Cost of services Cost of Goods and Services Sold Income taxes receivable Income Taxes Receivable, Current Capital expenditures Payments to Acquire Property, Plant, and Equipment Other Other Liabilities, Noncurrent Forgone Recovery due to Violation of Home Country Law, Amount Forgone Recovery due to Violation of Home Country Law, Amount Commitments and Contingencies Commitments and Contingencies Stock-Based Awards Share-Based Payment Arrangement [Policy Text Block] Schedule of reconciliations of the effective tax rates to the federal statutory rate Schedule of Effective Income Tax Rate Reconciliation [Table Text Block] Tariff-based revenues Tariff-based Revenues [Member] Tariff-based Revenues [Member] Schedule of Debt Instruments [Table] Schedule of Debt Instruments [Table] A table or schedule providing information pertaining to short-term and long-term debt instruments or arrangements, including identification, terms, features, collateral requirements and other information necessary to a fair presentation. Termination Date Trading Arrangement Termination Date Power purchased for pumping Power Purchased for Pumping This element represents Power purchased for pumping expenses. 2026 Lessee, Operating Lease, Liability, to be Paid, Year Two Components of allowance for doubtful accounts Allowance for Doubtful Accounts Receivable [Abstract] -- None. No documentation exists for this element. -- 2028 Purchase Obligation, to be Paid, Year Four Other Electric Plant General [Member] Plant used in general activity of the electric utility company. Refunds on advances for construction Refunds On Advances For Construction Refunds On Advances For Construction Debt Instrument [Axis] Debt Instrument [Axis] Receivable from U.S. government (Note 2) Account Receivable from US Government, Net,Noncurrent Account Receivable from US Government, Net,Noncurrent Other assets Assets Other than Property Plant and Equipment, Net Sum of the carrying amounts as of the balance sheet date of all assets except utility plant that are recognized. Funded Status: Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract] Net Income Net Income Net Income (Loss) Attributable to Parent Trading Arrangement: Trading Arrangement [Axis] Contracted services Revenue from Contract with Customer, Including Assessed Tax Thereafter Defined Benefit Plan, Expected Future Benefit Payment, after Year Five for Next Five Years Pay vs Performance Disclosure, Table Pay vs Performance [Table Text Block] Water Utility Plant, at cost Utilities Water Property Plant and Equipment Gross This element represents the gross amount, at the balance sheet date, of long-lived water related physical assets used in the normal conduct of business and not intended for resale owned by a utility entity used in the operations of the entity. Line of credit facility, current borrowing capacity Line of Credit Facility, Current Borrowing Capacity Schedule of pension and post-retirement plans' investment assets measured at fair value Schedule of Allocation of Plan Assets [Table Text Block] Equity Awards Adjustments, Excluding Value Reported in Compensation Table Equity Awards Adjustments, Excluding Value Reported in the Compensation Table [Member] Entity File Number Entity File Number Thereafter Purchase Obligation, to be Paid, after Year Five Consolidated Entities [Domain] Consolidated Entities [Domain] Contract assets Increase(Decrease) in Contract Assets The net change during the reporting period in contact assets Income Statement [Abstract] Income Statement [Abstract] Entity Address, Address Line One Entity Address, Address Line One Total Defined Benefit Plan, Expected Future Benefit Payment Defined Benefit Plan, Expected Future Benefit Payment Federal Current Federal Tax Expense (Benefit) Schedule of reconciliation of total utility plant (a key figure for rate-making) to total consolidated assets Schedule Showing Reconciliation of Total Utility Plant to Total Consolidated Assets [Table Text Block] Tabular disclosure of reconciliation of total utility plant (a key figure for rate-making) to total consolidated assets. Dividends on Common Shares Dividends, Common Stock Property Plant and Equipment and Investments Other and Goodwill Net Property Plant and Equipment and Investments Other This element represents the aggregate amount of capitalized assets classified as property, plant and equipment, and other noncurrent investments not otherwise defined in the taxonomy as of the balance sheet date. Supply cost balancing accounts Supply Cost Balancing Accounts This element represents the supply cost balancing accounts maintained for under-collections and over-collections of revenues designed to recover such costs. Name Forgone Recovery, Individual Name Operating Lease, Weighted Average Remaining Lease Term Operating Lease, Weighted Average Remaining Lease Term Loss Contingency, Nature [Domain] Loss Contingency, Nature [Domain] 2029 Purchase Obligation, to be Paid, Year Five Other — net Other Noncash Income (Expense) Award Timing MNPI Considered Award Timing MNPI Considered [Flag] Deferred tax liabilities: Components of Deferred Tax Liabilities [Abstract] Schedule of estimated future benefit payments Schedule of Expected Benefit Payments [Table Text Block] Contract assets Contract with Customer, Asset, after Allowance for Credit Loss Outstanding Aggregate Erroneous Compensation Amount Outstanding Aggregate Erroneous Compensation Amount Public Utility [Axis] Public Utility [Axis] PEO Actually Paid Compensation Amount PEO Actually Paid Compensation Amount Adjustment to Compensation: Adjustment to Compensation [Axis] Fair Value of Financial Instruments Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract] Under/(over)-collection (alternative revenue program) Alternative Revenue Programs, Net Alternative Revenue Programs, Net Period of Fixed Price Contracts to Maintain Water Systems at Various Military Bases Period of fixed price contracts to maintain water systems at various military bases Period of Fixed Price Contracts to Maintain Water Systems at Various Military Bases Represents the period of fixed price contracts to operate and maintain the water and/or wastewater systems at various military bases. Pension Adjustments Service Cost Pension Adjustments Service Cost [Member] Related Party [Axis] Related and Nonrelated Parties [Axis] Weighted Average Number of Shares Outstanding (in shares) Weighted average Common Shares outstanding, basic Weighted Average Number of Shares Outstanding, Basic Stock Price or TSR Estimation Method Stock Price or TSR Estimation Method [Text Block] Target Asset Allocations: Defined Benefit Plan, Plan Assets, Target Allocation, Percentage Audit Information [Abstract] Audit Information [Abstract] Name Awards Close in Time to MNPI Disclosures, Individual Name Prefunded plan costs Unfunded accrued cost Defined Benefit Plan Amounts Unfunded Accrued Pension Cost Represents the amount of unfunded accrued pension cost recognized in regulatory assets that is associated with the defined benefit pension plans and other post-retirement defined benefit plans. Asset retirement obligations (Note 1) Asset retirement obligations [Member] Asset retirement obligations Entity Filer Category Entity Filer Category Revenue, Remaining Performance Obligation, Amount Revenue, Remaining Performance Obligation, Amount Contingencies Loss Contingencies [Line Items] Asset Retirement Obligation, Liabilities Settled Asset Retirement Obligation, Liabilities Settled Total Property Plant And Equipment Before Construction Work In Progress, Unconsolidated Tangible assets that are held by an entity for use in the production or supply of goods and services, for rental to others, or for administrative purposes and that are expected to provide economic benefit for more than one year; net of accumulated depreciation but before construction work in progress. Examples include land, buildings, machinery and equipment, and other types of furniture and equipment including, but not limited to, office equipment, furniture and fixtures, and computer equipment and software, unconsolidated. GSWC GSWC Golden State Water Company [Member] Golden State Water Company [Member] Utility Accounting Public Utilities, Policy [Policy Text Block] Statistical Measurement [Domain] Statistical Measurement [Domain] Capital additions Segment, Expenditure, Addition to Long-Lived Assets Regulatory-liability-related Deferred Tax Assets Regulatory Assets and Liabilities Related to I T C and Excess Deferred Taxes Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences derived from regulatory assets and liabilities related to ITC and excess deferred taxes. Supplemental lease information Lease, Cost [Table Text Block] Percentage of target amount of performance shares Percentage of Target Amount of Performance Shares Percentage of Target Amount of Performance Shares Debt securities Debt Securities [Member] Sale of Stock, remaining available for sale Sale of Stock, remaining available for sale Sale of Stock, remaining available for sale under the ATM equity program Other Other liabilities Other Liabilities, Current Details of reportable segment Segment Reporting Information [Line Items] Flow-through on removal costs Income Tax Reconciliation Cost of Removal The portion of the difference between total income tax expense or benefit as reported in the Income Statement and the expected income tax expense or benefit computed by applying the domestic federal statutory income tax rates to pretax income from continuing operations attributable to flow-through on Cost of Removal. All Trading Arrangements All Trading Arrangements [Member] Compensation Actually Paid vs. Net Income Compensation Actually Paid vs. Net Income [Text Block] Vesting period Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period Rule 10b5-1 Arrangement Adopted Rule 10b5-1 Arrangement Adopted [Flag] Awards Close in Time to MNPI Disclosures Awards Close in Time to MNPI Disclosures [Table] Derivative instruments Derivative [Line Items] Income taxes paid Income Taxes Paid, Net 2025 Long-Term Debt and Capital Lease Obligations, Repayments of Principal in Next 12 Months Utility Plant and Intangible Assets Utility Plant and Intangible Assets Disclosure [Text Block] Entire disclosure of property, plant, equipment and intangible assets of the reporting entity. Pay vs Performance Disclosure [Line Items] Peer Group Total Shareholder Return Amount Peer Group Total Shareholder Return Amount Allowance for doubtful accounts related to other accounts receivable Allowance for Doubtful Accounts Related to other Accounts Receivable Represents the provision for doubtful accounts related to other accounts receivable. Utility Plant Utilities Property Plant and Equipment Gross [Abstract] -- None. No documentation exists for this element. -- Derivative [Table] Derivative [Table] SERP Supplemental Employee Retirement Plan [Member] Deferred Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract] Period for refund of advances for construction Period of Refund of Customer Advances for Construction Represents the period for the refund of advances for construction. Military Privatization Long-Term Contracts or Programs Disclosure [Text Block] Other Performance Measure, Amount Other Performance Measure, Amount 2027 Finite-Lived Intangible Asset, Expected Amortization, Year Three Leases Lessee, Operating Leases [Text Block] Common stock, shares outstanding Beginning Balance (in shares) Ending Balance (in shares) Common Stock, Shares, Outstanding Documents Incorporated by Reference Documents Incorporated by Reference [Text Block] Weighted Average Annual Interest Rate (as a percent) Short-Term Debt, Weighted Average Interest Rate, at Point in Time Intercompany receivables Intercompany note receivables Other Receivables, Net, Current Debt and Lease Obligation Total Debt and Lease Obligation Income taxes receivable/payable Increase (Decrease) in Income Taxes Operating lease liabilities Long-term lease obligations Operating Lease, Liability, Noncurrent Benefits/expenses paid Benefits paid Defined Benefit Plan, Benefit Obligation, Benefits Paid Environmental Costs Recognized, Capitalized Environmental Costs Recognized, Capitalized Contract liabilities (Note 2) Contract with Customer, Liability, Current Non-cash financing and investing activities and other cash flow information Schedule of Cash Flow Supplemental Disclosures [Line Items] -- None. No documentation exists for this element. -- Service cost Defined Benefit Plan, Service Cost Entity Tax Identification Number Entity Tax Identification Number Schedule of actual allocation of plan assets Schedule of Actual Allocation of Plan Assets [Table Text Block] Tabular disclosure of pension and post-retirement plan weighted-average asset allocations. Intangible Asset, Finite-Lived [Table] Intangible Asset, Finite-Lived [Table] Reconciliation of the beginning and ending aggregate carrying amount of the asset retirement obligations Asset Retirement Obligation, Roll Forward Analysis [Roll Forward] Schedule of Cash Flow Supplemental Disclosures [Table] Schedule of Cash Flow Supplemental Disclosures [Table] Schedule of supplemental cash flow information for the periods presented. Retirement Plan Type [Axis] Retirement Plan Type [Axis] Electric: Electric Electric Service Utility Operations [Member] Represents the electric service utility operations of the entity. Rate of compensation increase Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Rate of Compensation Increase Public Utilities, Regulatory Proceeding [Axis] Public Utilities, Regulatory Proceeding [Axis] Series A Senior Notes 5.22 Percent Due 2038 Series A Senior Notes 5.22 Percent Due 2038 [Member] Series A Senior Notes 5.22 Percent Due 2038 Sale of Stock, Consideration Received on Transaction Sale of Stock, Consideration Received on Transaction Income taxes payable Taxes Payable, Current Intersegment Eliminations Intersegment Eliminations [Member] Interest coverage ratio Debt Instrument Covenant Interest Coverage Ratio Represents the interest coverage ratio required to be maintained for debt instrument. Other operation Other Cost and Expense, Operating Plan Name [Axis] Plan Name [Axis] Income taxes receivable Income Taxes Receivable Equity Components [Axis] Equity Components [Axis] Undistributed earnings for dilutive stock-based awards Dilutive Securities, Effect on Basic Earnings Per Share, Options and Restrictive Stock Units Intercompany receivable Other Assets, Current Thereafter Long-Term Debt and Capital Lease Obligations, Maturities, Repayments of Principal after Year Five Accounts Receivable Accounts Receivable [Policy Text Block] Total recognized in net periodic pension cost and regulatory asset (liability) Total recognized in net periodic pension cost and regulatory asset (liability) Defined Benefit Plan, Net Periodic Benefit Cost and Cost Recognized in Regulatory Assets Represents the amount recognized in net periodic pension cost and regulatory asset. Capitalized equity-based compensation cost Share-Based Payment Arrangement, Amount Capitalized Amounts recognized in regulatory assets (liabilities) consist of: Defined Benefit Plan Amounts Recognized in Regulatory Assets, Liability [Abstract] -- None. No documentation exists for this element. -- Contract assets (Note 2) Contract with Customer, Asset, before Allowance for Credit Loss, Current Schedule of reconciliation of Registrant's net income and weighted average Common Shares outstanding for calculating basic net income per share Schedule of Earnings Per Share, Basic, by Common Class, Including Two Class Method [Table Text Block] Fully Diluted Earnings Per Share Earnings Per Share, Diluted [Abstract] Water Regulated Operating Revenue, Water Non-Cash Transactions: Cash Flow, Noncash Investing and Financing Activities Disclosure [Abstract] 2029 Lessee, Operating Lease, Liability, to be Paid, Year Five Weighted Average Weighted Average [Member] Aggregate Grant Date Fair Value of Equity Award Amounts Reported in Summary Compensation Table Aggregate Grant Date Fair Value of Equity Award Amounts Reported in Summary Compensation Table [Member] Operating Lease, Expense Operating Lease, Expense Tax Adjustments, Release of Regulatory Liability Effective Income Tax Reconciliation, Excess deferred income taxes estimate change Effective Income Tax Reconciliation, Excess deferred income taxes estimate change Derivative Activity Volume Derivative Activity Volume Derivative Activity Volume Cash and cash equivalents, beginning of year Cash and cash equivalents, end of year Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents Receivable from U.S. government, less allowance for doubtful accounts (Note 2) Accounts Receivable from U S Government Net, Current This element represents the amount, at the balance sheet date, current portion of receivables that are derived from government contracts. Contributions in aid of construction — net Contributions in Aid of Construction Excess deferred income taxes (Note 11) Deferred Income Tax Charge [Member] Other regulatory liabilities Revenue Subject to Refund [Member] Unrecognized compensation cost Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount Current Assets Assets, Current [Abstract] Transmission and Distribution Public Utilities, Property, Plant and Equipment, Transmission and Distribution, Useful Life Financing Applications Financing Applications [Member] Financing Applications Consolidation Items [Axis] Consolidation Items [Axis] Fair Value of Financial Instruments, Policy Fair Value of Financial Instruments, Policy [Policy Text Block] Forgone Recovery due to Disqualification of Tax Benefits, Amount Forgone Recovery due to Disqualification of Tax Benefits, Amount Product and Service [Domain] Product and Service [Domain] Short-term Lease, Cost Short-Term Lease, Cost Vested (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value Prior service cost (credit) Defined Benefit Plan Amounts Recognized in Regulatory Asset, Liability Prior Service Cost (Credit) Represents the prior service cost (credit) recognized in regulatory asset (liability). Period of fixed price contracts to operate and maintain the water and/or wastewater systems at various military bases Period of Fixed Price Contracts to Operate and Maintain Water Systems at Various Military Bases Period of Fixed Price Contracts to Operate and Maintain Water Systems at Various Military Bases Represents the period of fixed price contracts to operate and maintain the water and/or wastewater systems at various military bases. Security Exchange Name Security Exchange Name 5.87% notes due 2028 Notes Payable 5.87 Percent Due 2028 [Member] Represents the 5.87 percent notes, due in 2028. Number of Restricted/Performance Share Units Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] State Current State and Local Tax Expense (Benefit) Forgone Recovery, Explanation of Impracticability Forgone Recovery, Explanation of Impracticability [Text Block] Proceeds from Stock Options Exercised, Distributed to Subsidiaries Proceeds from Stock Options Exercised, Distributed to Subsidiaries Proceeds from Stock Options Exercised, Distributed to Subsidiaries American States Utility Services American States Utility Services [Member] Represents activity related to American States Utility Services, Inc. (ASUS). Goodwill and Intangible Assets Disclosure [Abstract] Bundled Purchased Renewable Energy Credits Number Bundled Purchased Renewable Energy Credits Number Bundled Purchased Renewable Energy Credits Number Retirement Plan Name [Domain] Retirement Plan Name [Domain] Related Party Transactions Related Party Transactions [Policy Text Block] Disclosure of accounting policy related to transactions with related parties. Entity [Domain] Entity [Domain] Maximum borrowing capacity Maximum borrowing capacity Line of Credit Facility, Maximum Borrowing Capacity Percentage of total revenues Concentration Risk, Percentage Approved return on equity, percentage Public Utilities, Approved Return on Equity, Percentage Real Estate Funds Real Estate Funds [Member] Long-Term Purchase Commitment, Category of Item Purchased [Domain] Long-Term Purchase Commitment, Category of Item Purchased [Domain] Insider Trading Policies and Procedures Adopted Insider Trading Policies and Procedures Adopted [Flag] Utility plant utilized in continuing operations by major asset class Public Utility, Property, Plant and Equipment [Line Items] Reconciliation of Assets from Segment to Consolidated [Table] Reconciliation of Assets from Segment to Consolidated [Table] Electric Utilities Electric Property Plant and Equipment Gross This element represents the gross amount, at the balance sheet date, of long-lived electric related physical assets used in the normal conduct of business and not intended for resale owned by a utility entity used in the operations of the entity. Common stock, shares authorized Common Stock, Shares Authorized Additional year-end information for plans with an accumulated benefit obligation in excess of plan assets: Defined Benefit Plan, Plan with Accumulated Benefit Obligation in Excess of Plan Assets [Abstract] Investment tax credit Effective Income Tax Rate Reconciliation, Tax Credit, Investment, Amount Ratio of indebtedness to net capital Ratio of Indebtedness to Net Capital Percentage of rights vesting in the first two years from the date of grant Share Based Compensation Arrangement by Share Based Payment Award, Award Vesting Period of Thirty Three Percent, First Two Years Period in which 33% vesting rights is earned by awarded of the grant, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Long-term Debt, Type [Axis] Long-Term Debt, Type [Axis] Schedule of non-cash financing and investing activities and other cash flow information Schedule of Cash Flow, Supplemental Disclosures [Table Text Block] Entity Voluntary Filers Entity Voluntary Filers Amortization of actuarial (gain) loss Amortization of net (gain) loss Defined Benefit Plan, Amortization of Gain (Loss) Segment Reporting, Asset Reconciling Item [Line Items] Segment Reporting, Asset Reconciling Item [Line Items] Interest Expense, Nonoperating Interest expense Interest Expense, Nonoperating Total deferred tax (benefit) expense Deferred Income Tax Expense (Benefit) Discount rate Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate Rabbi Trust Trust for Benefit of Employees [Member] Equity, Capital Unit or Share [Table] Equity, Capital Unit or Share [Table] Accounts receivable — customers, less allowance for doubtful accounts Accounts Receivable, after Allowance for Credit Loss, Current Document and Entity Information Document and Entity Information -- None. No documentation exists for this element. -- Chang in control, term Change In Control, Term Change In Control, Term Other liabilities Increase (Decrease) in Other Operating Liabilities Pension Adjustments Prior Service Cost Pension Adjustments Prior Service Cost [Member] Fair value of plan assets at beginning of year Fair value of plan assets at end of year Fair Value Total investments measured at fair value Total investments measured at fair value Defined Benefit Plan, Plan Assets, Amount Bank debt Note payable to banks Schedule of Debt Instruments [Line Items] -- None. No documentation exists for this element. -- Non-union plan Other Postretirement Benefit Nonunion Plan Defined Benefit [Member] Represents information pertaining to the non-union plan covered under the post-retirement medical plans. Pension Benefits Adjustments, Footnote Pension Benefits Adjustments, Footnote [Text Block] New prior service cost Defined Benefit Plan Amounts Recognized in Regulatory Asset, Liability New Prior Service Cost (Credit) Defined Benefit Plan Amounts Recognized in Regulatory Asset, Liability New Prior Service Cost (Credit) 7.23% notes due 2031 Notes Payable 7.23 Percent Due 2031 [Member] Represents the 7.23 percent notes, due in 2031. Total Shareholder Return Vs Peer Group Total Shareholder Return Vs Peer Group [Text Block] Payments for Commissions Payments for Commissions Investments in subsidiaries Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures Interest Public Utilities, Allowance for Funds Used During Construction, Net Increase [Abstract] Document Annual Report Document Annual Report Schedule of estimated future minimum payments under purchased water supply commitments Purchase Commitment, Excluding Long-Term Commitment [Table Text Block] Vested (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period Private Placement Notes Private Placement Notes [Member] Private Placement Notes [Member] 2.17% notes due 2030 Notes Payable 2.17 Percent Due 2030 [Member] Notes Payable 2.17 Percent Due 2030 Intangible assets not subject to amortization Indefinite-Lived Intangible Assets (Excluding Goodwill) ContractInitialOrderValueToPerformAnEvaluationConstructionAndTransitionServices :ContractInitialOrderValueToPerformAnEvaluationConstructionAndTransitionServices :ContractInitialOrderValueToPerformAnEvaluationConstructionAndTransitionServices Amortization of intangible assets Amortization of Intangible Assets Contract liabilities Contract with Customer, Liability Accounting Policies [Abstract] Accounting Policies [Abstract] Operating Revenues Revenues [Abstract] Pumping Public Utilities Property Plant and Equipment Pumping Estimated Useful Life Represents the estimated useful life of property, plant and equipment (PPE) related to pumping owned by public utility. Unamortized investment tax credits Accumulated Deferred Investment Tax Credit Notes payable to banks Notes Payable to Bank, Current Current Fiscal Year End Date Current Fiscal Year End Date Less: imputed interest Lessee, Operating Lease, Liability, Undiscounted Excess Amount 2023/2024 general rate case memorandum accounts (unbilled revenue) 2023/2024 general rate case memorandum accounts (unbilled revenue) [Member] Discloses the amount of regulatory assets and liabilities pertaining to the general rate case memorandum accounts. Regulatory Asset [Domain] Regulatory Asset [Domain] PEO Name PEO Name Long-Term Debt Long-Term Debt, Current and Noncurrent [Abstract] Award Type [Domain] Award Type [Domain] Issuances of Common Shares under stock-based compensation plans ( in shares) Shares Issued, Shares, Share-Based Payment Arrangement, after Forfeiture Compensation Actually Paid vs. Company Selected Measure Compensation Actually Paid vs. Company Selected Measure [Text Block] Accrued pension and other post-retirement benefits Accrued pension and other post-retirement benefits Non-current liabilities Liability, Defined Benefit Plan, Noncurrent Regulatory liabilities Regulatory Liability, Noncurrent Non-PEO NEO Non-PEO NEO [Member] Restricted Stock Units Restricted Share Unit Including Performance Shares [Member] Restricted Share Unit Including Performance Shares [Member] Bay State Utility Service LLC ("BSUS") Bay State Utility Service LLC ("BSUS") [Member] Bay State Utility Service LLC ("BSUS") 2022/2023 general rate case memorandum accounts (unbilled revenue) 2022/2023 General Rate Case Memorandum Accounts ( unbilled revenue) [Member] 2022/2023 General Rate Case Memorandum Accounts ( unbilled revenue) Notes Payable Note payable to bank Notes Payable Employee Benefit Plans Retirement Benefits [Text Block] Other- net Effective Income Tax Rate Reconciliation, Other Adjustments, Amount Regulatory Liability [Axis] Regulatory Liability [Axis] New Accounting Pronouncements, Policy New Accounting Pronouncements, Policy [Policy Text Block] Unbilled receivable (Note 2) Unbilled receivable Unbilled Receivables, Current Regulatory assets (liabilities) Regulatory asset (liability) at beginning of year Regulatory asset (liability) at end of year Defined Benefit Plan Amounts Recognized in Regulatory Asset (Liability) Represents the amount recognized in regulatory asset (liability). Operating revenues and other income Sales Revenue Net and other Income Represents information pertaining to operating revenues and other income. Title of Individual with Relationship to Entity [Domain] Title and Position [Domain] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets by Major Class [Axis] Less — accumulated amortization Finite-Lived Intangible Assets, Accumulated Amortization Under Collection in Two Way Pension Balancing Account Under Collection in Two Way Pension Balancing Account [Member] Represents the two-way pension balancing account. Income Tax Disclosure [Table] Income Tax Disclosure [Table] Table representing disclosure pertaining to taxes on income. Name Measure Name Entity Interactive Data Current Entity Interactive Data Current Percentage of rights vesting in the third year from the date of grant Vesting Rights Percentage in Third Year from Grant Date Description of award terms as to how many shares or portion of an award are no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in the third year from the date of grant, thereby giving the employee the legal right to convert the award to shares, expressed as a percentage. Dividend Limitations Dividend Limitation Disclosure [Text Block] Entire disclosure of dividends limitations and restrictions of the reporting entity. Purchase commitments Purchase Commitment, Excluding Long-term Commitment [Line Items] Purchase Commitment, Excluding Long-Term Commitment [Line Items] Schedule of Public Utility Property Plant and Equipment Components [Table Text Block] Schedule of Public Utility Property Plant and Equipment Components [Table Text Block] Tabular disclosure of the components of public utility property, plant and equipment. Deferred tax assets: Components of Deferred Tax Assets [Abstract] Disaggregation of Revenue [Table] Disaggregation of Revenue [Table] Stock-based compensation expense Share-Based Payment Arrangement, Noncash Expense 2027 Purchase Obligation, to be Paid, Year Three Employees and directors Employees and Director [Member] Represents information pertaining to the employees and directors. Wildfire mitigation and other fire prevention related costs memorandum accounts Vegetation management and wildfire mitigation plans memos [Member] Vegetation management and wildfire mitigation plans memos Common stock entitled to be received under each award (in shares) Share Based Compensation Arrangement by Share Based Payment Award Common Stock Entitled to be Received under each Award Represents the common stock entitled to be received under each share-based payment award. Interest rate per annum (as a percent) Interest rate (as a percent) Debt Instrument, Interest Rate, Stated Percentage Changes in allowance for doubtful accounts Accounts Receivable, Allowance for Credit Loss [Roll Forward] Total common shareholders earnings, diluted Net Income (Loss) Available to Common Stockholders, Diluted Total other income and expenses Nonoperating Income (Expense) Concentration Risk Benchmark [Domain] Concentration Risk Benchmark [Domain] Auditor Firm ID Auditor Firm ID Operating Income Operating Income (Loss) Environmental Clean-Up and Remediation Environmental Clean-Up and Remediation [Member] Environmental Clean-Up and Remediation Initial Health care cost for employees of age 65 and over (as a percent) Defined Benefit Plan Initial Health Care Cost Trend Rate for Employees of Age Sixty Five and over Represents the initial health care cost for employees of age sixty-five and over. Number of reportable segments Number of Reportable Segments Total liabilities and capitalization Liabilities and Equity Rule 10b5-1 Arrangement Terminated Rule 10b5-1 Arrangement Terminated [Flag] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Regulatory and Other Assets Regulatory and Other Assets [Abstract] -- None. No documentation exists for this element. -- Number of registrants filing combined report Number of Registrants Filing Combined Report Represents the number of registrants filing combined report during the period. Purchase Commitment, Excluding Long-term Commitment [Table] Purchase Commitment, Excluding Long-Term Purchase Commitment [Table] Regulated Operations [Abstract] Regulated Operations [Abstract] Number of the contracts with 15-year contracts with the U.S. government Number of the contracts with 15-year contracts with the U.S. government Number of the contracts with 15-year contracts with the U.S. government Dividends paid Payments of Dividends Interest income Investment Income, Interest Finite-Lived Intangible Assets, Major Class Name [Domain] Finite-Lived Intangible Assets, Major Class Name [Domain] Less: Current maturities Long-Term Debt and Lease Obligation, Current Transmission and distribution Water Transmission and Distribution [Member] Represents the system used for the primary purpose of transmitting and distributing water to the consumer. Summary of the status of Registrant's outstanding restricted stock units to employees and directors Share-Based Payment Arrangement, Restricted Stock and Restricted Stock Unit, Activity [Table Text Block] Schedule of annual maturities of all long-term debt, including capitalized leases Schedule of Maturities of Long-Term Debt [Table Text Block] Underlying Security Market Price Change Underlying Security Market Price Change, Percent Expected return on plan assets Defined Benefit Plan, Expected Return (Loss) on Plan Assets Individual: Individual [Axis] Contract with Customer, Asset and Liability [Table] Contract with Customer, Asset and Liability [Table] Contract with Customer, Asset and Liability [Table] Product and Service [Axis] Product and Service [Axis] Statement Statement [Line Items] Total other assets Regulatory and Other Assets This element represents aggregate carrying amount, at the balance sheet date, of noncurrent regulatory assets held by public utility entities and other noncurrent assets not separately disclosed in the balance sheet. Summary of fair value, measured by net asset value, of the pension investment assets Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Table Text Block] Operating Expenses Operating Expenses [Abstract] Discount percentage for qualified low income water customers Discount Percentage For Qualified Low Income Water Customers Discount Percentage For Qualified Low Income Water Customers Benefits/expenses paid Defined Benefit Plan, Plan Assets, Benefits Paid Compensation Actually Paid vs. Total Shareholder Return Compensation Actually Paid vs. Total Shareholder Return [Text Block] Total change in regulatory asset (liability) Change in regulatory asset (liability) Defined Benefit Plan Cost Recognized in Regulatory Assets, Liability Represents the net amount of loss (gain) that are recognized as a component of regulatory assets (liability). Derivative, Term of Contract Derivative, Term of Contract Balance, at beginning of the period Balance, at end of the period Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability Value Other accounts receivable Increase (Decrease) in Accounts and Other Receivables Schedule of changes in the fair value of the derivative Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block] Minimum Minimum Minimum [Member] Reportable Legal Entities Reportable Legal Entities [Member] Adoption Date Trading Arrangement Adoption Date Related Party Transactions Related Party Transactions [Abstract] Minimum period of service for eligibility under the Pension Plan Defined Benefit Plan Minimum Period of Service for Eligibility Represents the minimum period of service required in order to participate in the plan. Alternative revenue program Alternative revenue program [Member] Alternative revenue program Provision for doubtful accounts Accounts Receivable, Credit Loss Expense (Reversal) Segments [Axis] Segments [Axis] Change in Fair Value as of Vesting Date of Prior Year Equity Awards Vested in Covered Year Change in Fair Value as of Vesting Date of Prior Year Equity Awards Vested in Covered Year [Member] Regulatory asset, amortization period Regulatory Asset, Amortization Period Effective income tax rate (as a percent) Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent Derivative Instrument [Axis] Derivative Instrument [Axis] Exercise Price Award Exercise Price Schedule of significant components of the deferred tax assets and liabilities from continuing operations Schedule of Deferred Tax Assets and Liabilities [Table Text Block] Other Regulatory Assets Other Regulatory Assets [Member] Other Regulatory Assets Arrangement Duration Trading Arrangement Duration Number of construction performance obligation Number of construction performance obligation Number of construction performance obligation Schedule of reconciliation of the beginning and ending aggregate carrying amount of the asset retirement obligations Schedule of Asset Retirement Obligations [Table Text Block] Common Shareholders' Equity: Equity, Attributable to Parent [Abstract] Subsidiaries Subsidiaries [Member] Regulatory-asset-related: depreciation and other Deferred Tax Liabilities, Regulatory Assets Other Water Plant General [Member] Represents the plant used in general activity of the water utility entity. Material Terms of Trading Arrangement Material Terms of Trading Arrangement [Text Block] Debt instrument, term Debt Instrument, Term Transmission and distribution Electric Transmission and Distribution Equipment [Member] Purchased Renewable Energy Credits Number Delivered in 2023 Purchased Renewable Energy Credits Number Delivered in 2023 Purchased Renewable Energy Credits Number Delivered in 2023 Estimated future minimum payments Purchase Obligation, Fiscal Year Maturity [Abstract] Purchased Renewable Energy Credits Number Delivered in 2024 Purchased Renewable Energy Credits Number Delivered in 2024 Purchased Renewable Energy Credits Number Delivered in 2024 Total equity funds Equity Funds [Member] Common Shares authorized for issuance but unissued under 401(k) Plan Defined Contribution Plan Common Stock Capital Shares Reserved for Future Issuance Represents the number of common shares authorized but unissued under the defined contribution plan. 2028 Finite-Lived Intangible Asset, Expected Amortization, Year Four All Individuals All Individuals [Member] Amortization of net gain (loss) Amortization of net loss Defined Benefit Plan Amortization of Gains (Losses) Regulatory Assets Represents the amortization of net losses that are recognized as a component of regulatory assets (liability). Income Tax Disclosure [Abstract] Income Tax Disclosure [Abstract] Entities [Table] Entities [Table] Other, net Other Nonoperating Income (Expense) State Water Project due 2035 State Water Project Due 2035 [Member] Represents state water project obligation, due in 2035. Basic Earnings Per Share, Basic, Two Class Method [Abstract] Post-Retirement Medical Benefits Other Postretirement Benefits Plan [Member] Net regulatory assets Net regulatory assets Net Regulatory Assets Statement of Stockholders' Equity [Abstract] Statement of Stockholders' Equity [Abstract] Gain on sale of assets Gain (Loss) on Sale of Assets and Asset Impairment Charges Asset Retirement Obligation, Legally Restricted Assets, Fair Value Asset Retirement Obligation, Legally Restricted Assets, Fair Value Unrecognized compensation cost related to performance awards Share-Based Payment Arrangement, Nonvested Award, Excluding Option, Cost Not yet Recognized, Amount Debt Instrument Redemption Premium above Treasury Yield Debt Instrument Redemption Premium above Treasury Yield Debt Instrument Redemption Premium above Treasury Yield Other Property and Investments Other Property and Investments Property Plant and Equipment and Investments Other Net This element represents capitalized assets classified as property, plant and equipment and other noncurrent investments not otherwise defined in the taxonomy. Changes in Plan Assets: Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] Maintenance Utilities Operating Expense, Maintenance and Operations Current liabilities Liability, Defined Benefit Plan, Current Advance for Construction and Contributions in Aid Customer Advances or Deposits [Policy Text Block] Disclosure of accounting policy for advances for construction and contributions in aid of constructions. Diluted Earnings Per Share, Diluted, Two Class Method [Abstract] Related Party [Domain] Related and Nonrelated Parties [Domain] Total other credits Total other credits Liabilities, Noncurrent 4.949% note due 2037 Notes Payable 4.949 Percent Due 2037 [Member] Notes Payable 4.949 Percent Due 2037 Regulated utility plant, at cost Regulated Utilities Property Plant and Equipment Gross [Abstract] -- None. No documentation exists for this element. -- Dividend equivalent rights on stock-based awards not paid in cash Dividends Equivalent Rights on Share Based Compensation Not Paid in Cash Net of Tax This element represents equity impact of dividend equivalent rights on stock-based awards which is not paid in cash during the reporting period. Electric Power Purchase Commitments Electric Power Purchase Commitments [Member] Represents activity related to commitments to purchase power. Deferred income taxes Deferred Income Tax Liabilities, Net (Gain) loss on investments held in a trust (Gain) loss on investments held in a trust Unrealized Gain (Loss) on Investments Period to meet the performance goals Share-Based Compensation Arrangement by Share-Based Payment Award, Award Requisite Service Period Total operating expenses Utilities Operating Expense Number of participants in the Pension Plan Defined Benefit Plan, Number of Employees Covered Defined Benefit Plan, Number of Employees Covered Federal Deferred Federal Income Tax Expense (Benefit) Schedule of reconciliation of Registrant's net income and weighted average Common Shares outstanding for calculating diluted net income per share Schedule of Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Table Text Block] Share Repurchase Program [Domain] Share Repurchase Program [Domain] Cash and Cash Equivalents Cash and Cash Equivalents, Policy [Policy Text Block] Payments of Stock Issuance Costs Payments of Stock Issuance Costs Contingencies Commitments and Contingencies Disclosure [Text Block] Change in Projected Benefit Obligation: Change in Benefit Obligation: Defined Benefit Plan, Change in Benefit Obligation [Roll Forward] Impairment of long-lived assets Impairment, Long-Lived Asset, Held-for-Use Measure: Measure [Axis] Dividends paid Payments of dividends from subsidiaries Payments of Dividends from Subsidiaries Cash outflow from subsidiaries in the form of capital distributions and dividends to common shareholders, preferred shareholders and noncontrolling interests. Issuances of Common Shares under stock-based compensation plans Shares Issued, Value, Share-Based Payment Arrangement, after Forfeiture Issuance of Common Shares from an at-the-market program, net of issuance costs (in Shares) Exercise of stock options and other issuance of Common Shares Stock Issued During Period, Shares, New Issues 2025 Defined Benefit Plan, Expected Future Benefit Payment, Year One Unfunded Commitments Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Unfunded Commitments Entity Emerging Growth Company Entity Emerging Growth Company Accounting Policies [Line Items] Accounting Policies [Line Items] -- None. No documentation exists for this element. -- Receipt of advances for and contributions in aid of construction Proceeds From Contribution In Aid Of Construction And Repayments Of Advances For Construction Proceeds From Contribution In Aid Of Construction And Repayments Of Advances For Construction Provision charged to expense Provision for Doubtful Accounts Continuing Operation Amount of the current period expense charged against continuing operations, the offset which is generally to the allowance for doubtful accounts for the purpose of reducing receivables, including notes receivable, to an amount that approximates their net realizable value (the amount expected to be collected). 3.45% notes due 2029 Notes Payable 3.45 Percent Due 2029 [Member] Notes Payable 3.45 Percent Due 2029 [Member] Non-GAAP Measure Description Non-GAAP Measure Description [Text Block] Renewables Portfolio Standard Renewables Portfolio Standard [Member] Represents the regulatory liabilities arising from Renewables Portfolio Standard. Accumulated benefit obligation Defined Benefit Plan, Plan with Accumulated Benefit Obligation in Excess of Plan Assets, Accumulated Benefit Obligation Income tax effect, excess deferred income taxes estimate change Income Tax Effect, Excess deferred income taxes estimate change Income Tax Effect, Excess deferred income taxes estimate change Equity Component [Domain] Equity Component [Domain] Net amount recognized Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position Additional 402(v) Disclosure Additional 402(v) Disclosure [Text Block] Entity Shell Company Entity Shell Company Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code 2028 Defined Benefit Plan, Expected Future Benefit Payment, Year Four Statement [Table] Statement [Table] Regulatory assets/liabilities Increase (Decrease) in Regulatory Assets and Liabilities Schedule of components of intangible assets Schedule of Finite Lived and Indefinite Lived Intangible Assets by Major Class [Table Text Block] Tabular disclosure of the characteristics, including initial carrying value, residual amount, weighted average useful life, of indefinite and finite lived intangible assets by major class. A major class is composed of intangible assets that can be grouped together because they are similar, either by nature or by their use in the operations of the entity. Counterparty Name [Axis] Counterparty Name [Axis] Summary of Significant Accounting Policies Significant Accounting Policies [Text Block] Real estate funds Real Estate [Member] Consolidation Items [Domain] Consolidation Items [Domain] Deferred revenues Deferred Revenue, Revenue Recognized Interest Paid, Excluding Capitalized Interest, Operating Activities Interest Paid, Excluding Capitalized Interest, Operating Activities Wastewater Wastewater [Member] Wastewater [Member] Concentration Risk Benchmark [Axis] Concentration Risk Benchmark [Axis] Level 1 Fair Value, Inputs, Level 1 [Member] Total current assets Total current assets Assets, Current Statement of Cash Flows [Abstract] Statement of Cash Flows [Abstract] Capitalization Capitalization, Long-Term Debt and Equity [Abstract] Current and deferred components of income tax expense from continuing operations Income Tax Expense (Benefit), Continuing Operations [Abstract] Schedule of Long-term Debt Instruments [Table] Schedule of Long-Term Debt Instruments [Table] Employer contributions Defined Benefit Plan, Plan Assets, Contributions by Employer Supply costs Utilities Operating Expense, Products and Services Revenue impact due to lower cost of debt Revenue impact due to lower cost of debt Revenue impact due to lower cost of debt Entity Well-known Seasoned Issuer Entity Well-known Seasoned Issuer Change in Accounting Estimate, Type [Domain] Change in Accounting Estimate, Type [Domain] Materials and supplies Increase (Decrease) in Materials and Supplies Taxes on Income Income Tax Disclosure [Text Block] 2028 Lessee, Operating Lease, Liability, to be Paid, Year Four Debt Issuance Costs and Redemption Premiums Debt, Policy [Policy Text Block] Operating Lease, Weighted Average Discount Rate, Percent Operating Lease, Weighted Average Discount Rate, Percent Contract with Customer, Asset and Liability [Line Items] Contract with Customer, Asset and Liability [Line Items] [Line Items] for Contract with Customer, Asset and Liability [Table] Net cash provided (used) Net Cash Provided by (Used in) Financing Activities Non-regulated utility property, at cost Non Utilities Property Plant and Equipment, Gross This element represents the gross amount, at the balance sheet date, of non utility property assets used in the normal conduct of business and not intended for resale owned by a utility entity. Credit Facility [Axis] Credit Facility [Axis] Loss Contingency Nature [Axis] Loss Contingency Nature [Axis] Long-term debt-GSWC Long-Term Debt, Fair Value Total Utilities Property Plant and Equipment, Gross This element represents the gross amount, at the balance sheet date, of long-lived physical assets used in the normal conduct of business and not intended for resale owned by a utility entity used in the operations of the entity. Entity Registrant Name Entity Registrant Name Derivative, term of contract Period of Agreement for Purchase of Renewable Energy Credits Represents the period of agreement with a third party to purchase renewable energy credits. Adjustment to Non-PEO NEO Compensation Footnote Adjustment to Non-PEO NEO Compensation Footnote [Text Block] Depreciation and amortization Depreciation and amortization expense Depreciation, Depletion and Amortization State Deferred State and Local Income Tax Expense (Benefit) Fair Value as of Grant Date Award Grant Date Fair Value Customer Concentration Risk Customer Concentration Risk [Member] Non-current assets Assets for Plan Benefits, Defined Benefit Plan Other various third parties Other Various Third Parties [Member] Other Various Third Parties [Member] Level 2 Fair Value, Inputs, Level 2 [Member] Disaggregation of Revenue [Table Text Block] Disaggregation of Revenue [Table Text Block] Issuance of Common Shares from an at-the-market program, net of issuance costs Stock Issued During Period, Value, New Issues Unbilled Contracts Receivable Unbilled Contracts Receivable Schedule of share-based compensation expenses Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block] Restatement Determination Date: Restatement Determination Date [Axis] Dividend limitations Dividend Limitations Disclosure [Line Items] -- None. No documentation exists for this element. -- Title of 12(b) Security Title of 12(b) Security Concentration Risk Type [Axis] Concentration Risk Type [Axis] Common shares, no par value Common Stock, Value, Issued Immediate vesting for employees of certain age and above Share Based Compensation Arrangements by Share Based Payment Award Options, Minimum Age for Awards to Vest Immediately Share Based Compensation Arrangements by Share Based Payment Award Options, Minimum Age for Awards to Vest Immediately Document Financial Statement Error Correction [Flag] Document Financial Statement Error Correction [Flag] 2025 Lessee, Operating Lease, Liability, to be Paid, Next Rolling 12 Months Expected future employer's contribution Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year Amortization of prior service (cost) credit Amortization of prior service credit Defined Benefit Plan Amortization of Prior Service Cost Credit Regulatory Assets Represents the amortization of prior service cost (credit) that are recognized as a component of regulatory assets (liability). Amounts recognized on the balance sheets: Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position [Abstract] Share-based Payment Arrangement [Abstract] Share-Based Payment Arrangement [Abstract] Obligation at the beginning of the period Obligation at the end of the period Asset Retirement Obligation Regulatory assets Regulatory Asset, Noncurrent Military Privatization Military Privatization -- None. No documentation exists for this element. -- Water Revenue Adjustment Mechanism Water Revenue Adjustment Mechanism [Member] Represents the regulatory assets arising from water revenue adjustment mechanism. Deferred Tax Assets, Other Deferred Tax Assets, Other Intangible assets Finite-Lived Intangible Assets [Line Items] Generation Public Utilities, Property, Plant and Equipment, Generation, Useful Life Cash Flows From Financing Activities: Net Cash Provided by (Used in) Financing Activities [Abstract] 2029 Defined Benefit Plan, Expected Future Benefit Payment, Year Five Schedule of Regulatory Assets and Liabilities [Line Items] Schedule of Regulatory Assets and Liabilities [Line Items] Schedule of Regulatory Assets and Liabilities [Line Items] Increase (decrease) in taxes resulting from: Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Amount Regulatory liability Regulatory liability Regulatory Liability 2028 Long-Term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Four Annual maturities of all long-term debt, including capitalized leases Long-Term Debt, Fiscal Year Maturity [Abstract] Deferred tax liabilities Deferred Tax Liabilities, Gross Average Amount Outstanding Short-Term Debt, Average Outstanding Amount Basic earnings per Common Share (usd per share) Basic Earnings Per Common Share (usd per share) Earnings Per Share, Basic Proceeds from issuance of Common Shares to AWR (parent) Proceeds from Issuance of Common Stock Cash equivalents Cash and Cash Equivalents [Member] Award Timing MNPI Disclosure Award Timing MNPI Disclosure [Text Block] Capital stock Capital Unit [Line Items] Accrued payables for investment in utility plant Capital Expenditures Incurred but Not yet Paid Aggregate Pension Adjustments Service Cost Aggregate Pension Adjustments Service Cost [Member] Dividends Payable [Line Items] Dividends Payable [Line Items] Actual Asset Allocations: Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage Proceeds from the issuance of long-term debt, net of issuance costs Proceeds from Debt, Net of Issuance Costs Property and Depreciation Property, Plant and Equipment, Policy [Policy Text Block] Total current liabilities Total current liabilities Liabilities, Current Intangible assets Intangible Assets [Member] Represents information pertaining to the intangible assets. Revenue, Performance Obligation, Payment Terms Revenue, Performance Obligation, Payment Terms Payment terms in contract with customer. Includes, but is not limited to, timing of payment, existence of financing component, variability of consideration and constraint on variable consideration. Share Repurchase Program [Axis] Share Repurchase Program [Axis] Maximum number of years of credited service considered in determining retirement benefit Defined Benefit Plan Maximum Number of Years of Credited Service Considered in Computing Retirement Benefit Represents the maximum number of years of credited service used in computing the retirement benefit. Purchase Commitment, Excluding Long-term Commitment [Axis] Purchase Commitment, Excluding Long-Term Commitment [Axis] 2025 Finite-Lived Intangible Asset, Expected Amortization, Year One Amount paid by the State of California Underground Storage Tank Fund for clean-up and remediation of plant facilities Environmental Loss Contingencies Paid by Third Party Represents the amount of environmental remediation costs paid by the third party. Granted (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period Net loss (gain) Net (gain) loss Defined Benefit Plan Net Gains (Losses) Regulatory Assets Represents the net amount of loss (gain) that are recognized as a component of regulatory assets. Discount rate Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate Total operating revenues Operating revenues Revenues Stock-Based Compensation Plans Share-Based Payment Arrangement [Text Block] Disclosure of Restrictions on Dividends, Loans and Advances Disclosure [Abstract] Disclosure of Restrictions on Dividends, Loans and Advances Disclosure [Abstract] Entity Address, City or Town Entity Address, City or Town Government Contract Receivable Government Contract Receivable Schedule of Carrying Values and Estimated Fair Values of Debt Instruments Schedule of Carrying Values and Estimated Fair Values of Debt Instruments [Table Text Block] Asset Retirement Obligation Asset Retirement Obligation [Policy Text Block] Stock-based compensation recognized in the income statement, before taxes Share-Based Payment Arrangement, Expense Property and Depreciation Public Utilities, Property, Plant and Equipment [Abstract] Defined Contribution Plan, Employer Discretionary Contribution Amount Defined Contribution Plan, Employer Discretionary Contribution Amount Unbilled receivable Increase (Decrease) Receivable from Government The net change during the reporting period in amount receivable from the government. Loss Contingencies [Table] Loss Contingencies [Table] Forfeited (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Forfeited in Period Public Utilities, Allowance for Funds Used During Construction, Additions Public Utilities, Allowance for Funds Used During Construction, Additions Weighted-average assumptions used to determine benefit obligations at December 31: Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Benefit Obligation [Abstract] Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year [Member] Long-term debt — current Other Notes Payable, Current Revenues Revenue from Contract with Customer [Text Block] Document Fiscal Year Focus Document Fiscal Year Focus Filing term for the Wildfire Mitigation and Other Fire Prevention related costs balancing and memorandum accounts Filing term for the Wildfire Mitigation and Other Fire Prevention Related Costs Balancing and Memorandum Accounts Filing term for the Wildfire Mitigation and Other Fire Prevention Related Costs Balancing and Memorandum Accounts Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] 2029 Finite-Lived Intangible Asset, Expected Amortization, Year Five Document Period End Date Document Period End Date Earnings Reinvested in the Business Retained Earnings, Unappropriated [Member] Contributions and advances Deferred Tax Assets Contributions and Advances Represents the amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences derived from contributions and advances. Total lease payments Lessee, Operating Lease, Liability, to be Paid Restricted stock units outstanding (in shares) Restricted share units at the beginning of the period (in shares) Restricted share units at the end of the period (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number Insider Trading Arrangements [Line Items] 2027 Lessee, Operating Lease, Liability, to be Paid, Year Three Interest Allowance for Funds Used During Construction, Policy [Policy Text Block] Prepayments and other current assets Prepaid Expense and Other Assets, Current Document Transition Report Document Transition Report Total Purchase Obligation Purchase Obligation Cost of capital proceeding Cost of capital proceeding [Member] Cost of capital proceeding 5.22 % note due 2038 Notes Payable 5.22 Percent Due 2038 [Member] Notes Payable 5.22 Percent Due 2038 Entity Current Reporting Status Entity Current Reporting Status Restricted Stock Units Restricted Stock Units (RSUs) [Member] Accrued other taxes Franchise and Assessment Fees Taxes Represents franchise and assessment fees taxes. Flowed-through deferred income taxes, net (Note 11) Flow Through Taxes Net [Member] Represents the regulatory assets arising from flow-through taxes, net. Increase (Decrease) in Stockholders' Equity Increase (Decrease) in Stockholders' Equity [Roll Forward] Executive Category: Executive Category [Axis] Schedule of current and deferred components of income tax expense from continuing operations Schedule of Components of Income Tax Expense (Benefit) [Table Text Block] Letters of credit Letter of Credit [Member] Company Selected Measure Name Company Selected Measure Name