XML 84 R49.htm IDEA: XBRL DOCUMENT
v3.24.0.1

Summary of Significant Accounting Policies (Details) | 1 Months Ended | 12 Months Ended |  |  |  |
--- | --- | --- | --- | --- | --- | ---
Dec. 31, 2022 USD ($) | Feb. 28, 2022 USD ($) | Jan. 31, 2022 USD ($) | Dec. 31, 2023 USD ($) customer registrant state shares | Dec. 31, 2022 USD ($) shares | Dec. 31, 2021 USD ($) shares | Jul. 10, 2023 USD ($) | Jun. 15, 2023 USD ($) | Jan. 13, 2023 USD ($) | Jul. 12, 2021 USD ($)
Nature of Operations: |  |  |  |  |  |  |  |  |  |
Number of customers served | customer |  |  |  | 1,000,000 |  |  |  |  |  |
Number of States in which Entity Operates | state |  |  |  | 10 |  |  |  |  |  |
Number of registrants filing combined report | registrant |  |  |  | 2 |  |  |  |  |  |
Related Party Transactions |  |  |  |  |  |  |  |  |  |
Related Party Transaction, Amounts of Transaction |  |  |  | $ 5,000,000 | $ 5,200,000 | $ 5,300,000 |  |  |  |
Impairment of Long-Lived Assets |  |  |  |  |  |  |  |  |  |
Asset Retirement Obligation, Legally Restricted Assets, Fair Value |  |  |  | 0 |  |  |  |  |  |
Impairment of long-lived assets |  |  |  | 0 | 0 | $ 0 |  |  |  |
Goodwill |  |  |  |  |  |  |  |  |  |
Goodwill arose from acquisition of subcontractor's business |  |  |  | $ 1,100,000 | $ 1,100,000 |  |  |  |  |
Advances for Construction and Contributions in aid of Constructions |  |  |  |  |  |  |  |  |  |
Period for refund of advances for construction |  |  |  | 40 years |  |  |  |  |  |
Fair Value of Financial Instruments |  |  |  |  |  |  |  |  |  |
Long-term debt-GSWC |  |  |  | $ 556,214,000 |  |  |  |  |  |
Exercise of stock options and other issuance of Common Shares | shares |  |  |  | 18,371 | 25,956 | 47,182 |  |  |  |
Exercise of stock options and other issuance of Common Shares | shares |  |  |  | 18,371 | 25,956 | 47,182 |  |  |  |
Level 1 |  |  |  |  |  |  |  |  |  |
Fair Value of Financial Instruments |  |  |  |  |  |  |  |  |  |
Long-term debt-GSWC |  |  |  | $ 0 |  |  |  |  |  |
Level 3 |  |  |  |  |  |  |  |  |  |
Fair Value of Financial Instruments |  |  |  |  |  |  |  |  |  |
Long-term debt-GSWC |  |  |  | 0 |  |  |  |  |  |
Carrying Amount |  |  |  |  |  |  |  |  |  |
Fair Value of Financial Instruments |  |  |  |  |  |  |  |  |  |
Long-term debt-GSWC | $ 450,373,000 |  |  | 579,047,000 | $ 450,373,000 |  |  |  |  |
Fair Value | Level 2 |  |  |  |  |  |  |  |  |  |
Fair Value of Financial Instruments |  |  |  |  |  |  |  |  |  |
Long-term debt-GSWC | 424,151,000 |  |  | $ 556,214,000 | 424,151,000 |  |  |  |  |
GSWC |  |  |  |  |  |  |  |  |  |
Related Party Transactions |  |  |  |  |  |  |  |  |  |
Intercompany borrowings payment term |  |  |  | 24 months |  |  |  |  |  |
Property and Depreciation |  |  |  |  |  |  |  |  |  |
Depreciation on transportation equipment |  |  |  | $ 212,000 |  |  |  |  |  |
Estimated useful lives of utility plant, as authorized by the CPUC |  |  |  |  |  |  |  |  |  |
Generation |  |  |  | 40 years |  |  |  |  |  |
Fair Value of Financial Instruments |  |  |  |  |  |  |  |  |  |
Long-term debt-GSWC |  |  |  | $ 522,883,000 |  |  |  |  |  |
Water Utility Relief Funding For Overdue Water Bills Per Budget Act Of 2021 |  |  |  |  |  |  |  |  |  | $ 1,000,000,000
Relief funding |  |  | $ 9,500,000 | 3,500,000 | $ 9,500,000 |  |  |  |  |
Debt Instrument, Face Amount |  |  |  | 130,000,000 |  |  |  |  |  |
Stock Issued During Period, Value, New Issues |  |  |  | $ 10,000,000 |  |  |  |  |  |
Extended Water and Wastewater Arrearage Program Funding |  |  |  |  |  |  | $ 600,000,000 |  |  |
Exercise of stock options and other issuance of Common Shares | shares |  |  |  | 1 | 0 | 0 |  |  |  |
Exercise of stock options and other issuance of Common Shares | shares |  |  |  | 1 | 0 | 0 |  |  |  |
GSWC | Unsecured Private Placement Notes |  |  |  |  |  |  |  |  |  |
Fair Value of Financial Instruments |  |  |  |  |  |  |  |  |  |
Debt Instrument, Face Amount |  |  |  |  |  |  |  |  | $ 130,000,000 |
GSWC | Level 1 |  |  |  |  |  |  |  |  |  |
Fair Value of Financial Instruments |  |  |  |  |  |  |  |  |  |
Long-term debt-GSWC |  |  |  | $ 0 |  |  |  |  |  |
GSWC | Level 3 |  |  |  |  |  |  |  |  |  |
Fair Value of Financial Instruments |  |  |  |  |  |  |  |  |  |
Long-term debt-GSWC |  |  |  | 0 |  |  |  |  |  |
GSWC | Carrying Amount |  |  |  |  |  |  |  |  |  |
Fair Value of Financial Instruments |  |  |  |  |  |  |  |  |  |
Long-term debt-GSWC | 415,373,000 |  |  | 544,047,000 | $ 415,373,000 |  |  |  |  |
GSWC | Fair Value | Level 2 |  |  |  |  |  |  |  |  |  |
Fair Value of Financial Instruments |  |  |  |  |  |  |  |  |  |
Long-term debt-GSWC | 391,198,000 |  |  | $ 522,883,000 | 391,198,000 |  |  |  |  |
GSWC | Minimum |  |  |  |  |  |  |  |  |  |
Estimated useful lives of utility plant, as authorized by the CPUC |  |  |  |  |  |  |  |  |  |
Source of water supply |  |  |  | 20 years |  |  |  |  |  |
Pumping |  |  |  | 26 years |  |  |  |  |  |
Water treatment |  |  |  | 26 years |  |  |  |  |  |
Transmission and Distribution |  |  |  | 15 years |  |  |  |  |  |
Other plant |  |  |  | 5 years |  |  |  |  |  |
GSWC | Maximum |  |  |  |  |  |  |  |  |  |
Estimated useful lives of utility plant, as authorized by the CPUC |  |  |  |  |  |  |  |  |  |
Source of water supply |  |  |  | 60 years |  |  |  |  |  |
Pumping |  |  |  | 41 years |  |  |  |  |  |
Water treatment |  |  |  | 32 years |  |  |  |  |  |
Transmission and Distribution |  |  |  | 80 years |  |  |  |  |  |
Other plant |  |  |  | 62 years |  |  |  |  |  |
BVES |  |  |  |  |  |  |  |  |  |
Related Party Transactions |  |  |  |  |  |  |  |  |  |
Related Party Transaction, Amounts of Transaction |  |  |  | $ 3,500,000 | 2,700,000 | $ 2,800,000 |  |  |  |
Interest |  |  |  |  |  |  |  |  |  |
Public Utilities, Allowance for Funds Used During Construction, Additions |  |  |  | 14,000 | 106,000 | $ 216,000 |  |  |  |
Fair Value of Financial Instruments |  |  |  |  |  |  |  |  |  |
Relief funding | 152,000 | $ 321,000 |  |  | 473,000 |  |  |  |  |
Debt Instrument, Face Amount |  |  |  |  |  |  |  | $ 35,000,000 |  |
BVES | Carrying Amount |  |  |  |  |  |  |  |  |  |
Fair Value of Financial Instruments |  |  |  |  |  |  |  |  |  |
Long-term debt-GSWC | $ 35,000,000 |  |  | $ 35,000,000 | $ 35,000,000 |  |  |  |  |
Golden State Water Company and Bear Valley Electric Service, Inc. |  |  |  |  |  |  |  |  |  |
Property and Depreciation |  |  |  |  |  |  |  |  |  |
Aggregate composite rate for depreciation (as a percent) |  |  |  | 2.20% | 2.20% | 2.20% |  |  |  |
Depreciation |  |  |  | $ 38,300,000 | $ 37,300,000 | $ 35,500,000 |  |  |  |
Depreciation on transportation equipment |  |  |  | $ 851,000 | $ 382,000 | $ 379,000 |  |  |  |
Water: | GSWC |  |  |  |  |  |  |  |  |  |
Nature of Operations: |  |  |  |  |  |  |  |  |  |
Number of customers served | customer |  |  |  | 264,100 |  |  |  |  |  |
Electric: | BVES |  |  |  |  |  |  |  |  |  |
Nature of Operations: |  |  |  |  |  |  |  |  |  |
Number of customers served | customer |  |  |  | 24,800 |  |  |  |  |  |
Contracted services: | Maximum |  |  |  |  |  |  |  |  |  |
Nature of Operations: |  |  |  |  |  |  |  |  |  |
Period of fixed price contracts to operate and maintain the water and/or wastewater systems at various military bases |  |  |  | 50 years |  |  |  |  |  |
Contracted services: | American States Utility Services | Minimum |  |  |  |  |  |  |  |  |  |
Nature of Operations: |  |  |  |  |  |  |  |  |  |
Period of fixed price contracts to operate and maintain the water and/or wastewater systems at various military bases |  |  |  | 15 years |  |  |  |  |  |
Contracted services: | American States Utility Services | Maximum |  |  |  |  |  |  |  |  |  |
Nature of Operations: |  |  |  |  |  |  |  |  |  |
Period of fixed price contracts to operate and maintain the water and/or wastewater systems at various military bases |  |  |  | 50 years |  |  |  |  |  |
Contracted services: | Patuxent River Utility Services LLC("PRUS") |  |  |  |  |  |  |  |  |  |
Nature of Operations: |  |  |  |  |  |  |  |  |  |
Period of fixed price contracts to operate and maintain the water and/or wastewater systems at various military bases |  |  |  | 50 years |  |  |  |  |  |
Fair Value of Financial Instruments |  |  |  |  |  |  |  |  |  |
Initial price contract value and subject to annual economic price adjustments |  |  |  | $ 349,000,000 |  |  |  |  |  |
Contracted services: | Bay State Utility Service LLC ("BSUS") |  |  |  |  |  |  |  |  |  |
Fair Value of Financial Instruments |  |  |  |  |  |  |  |  |  |
Initial price contract value and subject to annual economic price adjustments |  |  |  | 45,000,000 |  |  |  |  |  |
:ContractInitialOrderValueToPerformAnEvaluationConstructionAndTransitionServices |  |  |  | $ 2,300,000 |  |  |  |  |  |

X
- Definition :ContractInitialOrderValueToPerformAnEvaluationConstructionAndTransitionServices + References No definition available. + Details
Name: | awr_ContractInitialOrderValueToPerformAnEvaluationConstructionAndTransitionServices
Namespace Prefix: | awr_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Extended Water and Wastewater Arrearage Program Funding + References No definition available. + Details
Name: | awr_ExtendedWaterAndWastewaterArrearageProgramFunding
Namespace Prefix: | awr_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition -- None. No documentation exists for this element. -- + References No definition available. + Details
Name: | awr_GoodwillAbstract
Namespace Prefix: | awr_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The aggregate amount of goodwill acquired in the prior period. + References No definition available. + Details
Name: | awr_GoodwillAcquiredInPriorPeriod
Namespace Prefix: | awr_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Initial price contract value and subject to annual economic price adjustments + References No definition available. + Details
Name: | awr_InitialPriceContractValueAndSubjectToAnnualEconomicPriceAdjustments
Namespace Prefix: | awr_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Intercompany borrowings payment term + References No definition available. + Details
Name: | awr_IntercompanyBorrowingsPaymentTerm
Namespace Prefix: | awr_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | instant

X
- Definition -- None. No documentation exists for this element. -- + References No definition available. + Details
Name: | awr_NatureOfOperationsAbstract
Namespace Prefix: | awr_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the number of customers who are served by the entity. + References No definition available. + Details
Name: | awr_NumberOfCustomers
Namespace Prefix: | awr_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the number of registrants filing combined report during the period. + References No definition available. + Details
Name: | awr_NumberOfRegistrantsFilingCombinedReport
Namespace Prefix: | awr_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the period of fixed price contracts to operate and maintain the water and/or wastewater systems at various military bases. + References No definition available. + Details
Name: | awr_PeriodOfFixedPriceContractsToOperateAndMaintainWaterSystemsAtVariousMilitaryBases
Namespace Prefix: | awr_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the period for the refund of advances for construction. + References No definition available. + Details
Name: | awr_PeriodOfRefundOfCustomerAdvancesForConstruction
Namespace Prefix: | awr_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition The amount of expense recognized in the current period that reflects the allocation of the cost of transportation equipment over the assets' useful lives. + References No definition available. + Details
Name: | awr_PublicUtilitiesPropertyPlantAndEquipmentDepreciationOnTransportationEquipment
Namespace Prefix: | awr_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Represents the estimated useful life of property, plant and equipment (PPE) related to pumping owned by public utility. + References No definition available. + Details
Name: | awr_PublicUtilitiesPropertyPlantAndEquipmentPumpingEstimatedUsefulLife
Namespace Prefix: | awr_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the estimated useful life of property, plant and equipment (PPE) related to source of water supply owned by public utility. + References No definition available. + Details
Name: | awr_PublicUtilitiesPropertyPlantAndEquipmentSourceOfWaterSupplyEstimatedUsefulLife
Namespace Prefix: | awr_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the estimated useful life of property, plant and equipment (PPE) related to water treatment owned by public utility. + References No definition available. + Details
Name: | awr_PublicUtilitiesPropertyPlantAndEquipmentWaterTreatmentEstimatedUsefulLife
Namespace Prefix: | awr_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition COVID relief funds through the Extended Arrearage Program + References No definition available. + Details
Name: | awr_ReliefFunding
Namespace Prefix: | awr_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Water Utility Relief Funding For Overdue Water Bills Per Budget Act Of 2021 + References No definition available. + Details
Name: | awr_WaterUtilityReliefFundingForOverdueWaterBillsPerBudgetActOf2021
Namespace Prefix: | awr_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- References No definition available. + Details
Name: | us-gaap_AssetImpairmentChargesAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Carrying amount of an asset that is legally restricted for purposes of settling an asset retirement obligation. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 410 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481850/410-20-50-1 + Details
Name: | us-gaap_AssetRetirementObligationLegallyRestrictedAssetsFairValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- References No definition available. + Details
Name: | us-gaap_CustomerAdvancesOrDepositsNoncurrentAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Face (par) amount of debt instrument at time of issuance. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 835 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482900/835-30-50-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1B -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481139/470-20-50-1B Reference 3: http://www.xbrl.org/2003/role/exampleRef -Topic 470 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 69B -Publisher FASB -URI https://asc.fasb.org//1943274/2147481568/470-20-55-69B Reference 4: http://www.xbrl.org/2003/role/exampleRef -Topic 470 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 69C -Publisher FASB -URI https://asc.fasb.org//1943274/2147481568/470-20-55-69C Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482925/835-30-45-2 Reference 6: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 55 -Paragraph 8 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482949/835-30-55-8 + Details
Name: | us-gaap_DebtInstrumentFaceAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The amount of expense recognized in the current period that reflects the allocation of the cost of tangible assets over the assets' useful lives. Includes production and non-production related depreciation. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 45 -Paragraph 28 -Subparagraph (b) -SubTopic 10 -Topic 230 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482740/230-10-45-28 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482099/360-10-50-1 + Details
Name: | us-gaap_Depreciation
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_FinancialInstrumentsFinancialLiabilitiesBalanceSheetGroupingsAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The aggregate amount of write-downs for impairments recognized during the period for long lived assets held for use (including those held for disposal by means other than sale). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 45 -Paragraph 28 -Subparagraph (b) -SubTopic 10 -Topic 230 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482740/230-10-45-28 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 360 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482099/360-10-50-2 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 45 -Paragraph 4 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482130/360-10-45-4 + Details
Name: | us-gaap_ImpairmentOfLongLivedAssetsHeldForUse
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. + References No definition available. + Details
Name: | us-gaap_LongTermDebtFairValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The number of states the entity operates in as of the balance sheet date. + References No definition available. + Details
Name: | us-gaap_NumberOfStatesInWhichEntityOperates
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Total increase in earnings in the period representing the cost of equity (based on assumed rate of return) and/or borrowed funds (based on interest rate) used to finance construction of regulated assets, which is expected to be recovered through rate adjustments. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 45 -Paragraph 28 -Subparagraph (b) -SubTopic 10 -Topic 230 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482740/230-10-45-28 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 980 -SubTopic 360 -Section 25 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org//1943274/2147481711/980-360-25-1 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 980 -SubTopic 340 -Section 50 -Paragraph 3 -Publisher FASB -URI https://asc.fasb.org//1943274/2147481878/980-340-50-3 + Details
Name: | us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionAdditions
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionNetIncreaseAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_PublicUtilitiesPropertyPlantAndEquipmentAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Composite depreciation rate for public utility plants in service. + References No definition available. + Details
Name: | us-gaap_PublicUtilitiesPropertyPlantAndEquipmentDisclosureOfCompositeDepreciationRateForPlantsInService
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Useful life of utility generation assets owned by public utility, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References No definition available. + Details
Name: | us-gaap_PublicUtilitiesPropertyPlantAndEquipmentGenerationUsefulLife
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_PublicUtilitiesPropertyPlantAndEquipmentNetAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Useful life of other property, plant and equipment (PPE) owned by public utility, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References No definition available. + Details
Name: | us-gaap_PublicUtilitiesPropertyPlantAndEquipmentOtherPropertyPlantAndEquipmentUsefulLife
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Useful life of utility transmission and distribution equipment owned by public utility, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References No definition available. + Details
Name: | us-gaap_PublicUtilitiesPropertyPlantAndEquipmentTransmissionAndDistributionUsefulLife
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of transactions with related party during the financial reporting period. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 850 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483326/850-10-50-1 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 850 -SubTopic 10 -Section 50 -Paragraph 3 -Publisher FASB -URI https://asc.fasb.org//1943274/2147483326/850-10-50-3 + Details
Name: | us-gaap_RelatedPartyTransactionAmountsOfTransaction
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_RelatedPartyTransactionsAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of new stock issued during the period. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 50 -Paragraph 2 -SubTopic 10 -Topic 505 -Publisher FASB -URI https://asc.fasb.org//1943274/2147481112/505-10-50-2 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 505 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481004/946-505-50-2 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 3 -Subparagraph (SX 210.6-09(4)(b)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483575/946-220-S99-3 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 3 -Subparagraph (SX 210.6-03(i)(1)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479886/946-10-S99-3 Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(28)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1 Reference 6: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 505 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480008/505-10-S99-1 Reference 7: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(29)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1 + Details
Name: | us-gaap_StockIssuedDuringPeriodSharesNewIssues
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Equity impact of the value of new stock issued during the period. Includes shares issued in an initial public offering or a secondary public offering. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 50 -Paragraph 2 -SubTopic 10 -Topic 505 -Publisher FASB -URI https://asc.fasb.org//1943274/2147481112/505-10-50-2 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Topic 946 -SubTopic 830 -Name Accounting Standards Codification -Section 55 -Paragraph 11 -Publisher FASB -URI https://asc.fasb.org//1943274/2147480167/946-830-55-11 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 205 -Name Accounting Standards Codification -Section 45 -Paragraph 4 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480767/946-205-45-4 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 505 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481004/946-505-50-2 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 3 -Subparagraph (SX 210.6-09(4)(b)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483575/946-220-S99-3 Reference 6: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(28)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1 Reference 7: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 505 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480008/505-10-S99-1 Reference 8: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(29)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1 + Details
Name: | us-gaap_StockIssuedDuringPeriodValueNewIssues
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel1Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByMeasurementBasisAxis=us-gaap_CarryingReportedAmountFairValueDisclosureMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByMeasurementBasisAxis=us-gaap_EstimateOfFairValueFairValueDisclosureMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel2Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=awr_GoldenStateWaterCompanyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=awr_UnsecuredPrivatePlacementNotesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=awr_BearValleyElectricServiceIncMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=awr_GoldenStateWaterCompanyAndBearValleyElectricServiceIncMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=awr_WaterServiceUtilityOperationsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=awr_ElectricServiceUtilityOperationsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=awr_ContractedServicesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=awr_AmericanStatesUtilityServicesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=awr_PatuxentRiverUtilityServicesLLCPRUSMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=awr_BayStateUtilityServiceLLCBSUSMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |