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Represents the interest coverage ratio required to be maintained for debt instrument.

No definition available.

Name:	awr_DebtInstrumentCovenantInterestCoverageRatio
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Data Type:	num:percentItemType
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Represents the redemption premium as a percentage of the par value of debt instrument.

No definition available.

Name:	awr_DebtInstrumentRedemptionPremiumAsPercentageOfParValue
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Data Type:	num:percentItemType
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Represents the redemption premium as a percentage of the par value of debt instrument after the specified period.

No definition available.

Name:	awr_DebtInstrumentRedemptionPremiumAsPercentageOfParValueAfterSpecifiedPeriod
Namespace Prefix:	awr_
Data Type:	num:percentItemType
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Debt Instrument Redemption Premium above Treasury Yield

No definition available.

Name:	awr_DebtInstrumentRedemptionPremiumaboveTreasuryYield
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Represents the redemption price of the debt instrument as a percentage of the principal amount.

No definition available.

Name:	awr_DebtInstrumentRedemptionPriceAsPercentageOfPrincipalAmount
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Data Type:	num:percentItemType
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Ratio of Indebtedness to EBITDA

No definition available.

Name:	awr_RatioofIndebtednesstoEBITDA
Namespace Prefix:	awr_
Data Type:	xbrli:pureItemType
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Face (par) amount of debt instrument at time of issuance.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=34725769&loc=d3e28878-108400

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399

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Data Type:	xbrli:monetaryItemType
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Period Type:	instant

Contractual interest rate for funds borrowed, under the debt agreement.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

Name:	us-gaap_DebtInstrumentLineItems
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Data Type:	xbrli:stringItemType
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Period Type:	duration

Gross amount of debt extinguished.

No definition available.

Name:	us-gaap_ExtinguishmentOfDebtAmount
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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Indebtedness divided by net capital.

No definition available.

Name:	us-gaap_RatioOfIndebtednessToNetCapital1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	instant

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Name:	us-gaap_RangeAxis=us-gaap_MaximumMember
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Name:	us-gaap_CreditFacilityAxis=awr_PrivatePlacementNotesMember
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Name:	us-gaap_RangeAxis=us-gaap_MinimumMember
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Name:	dei_LegalEntityAxis=awr_AmericanStatesUtilityServicesMember
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Data Type:	na
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Name:	us-gaap_LongtermDebtTypeAxis=awr_SeniorNotesCobankMember
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