XML 53 R40.htm IDEA: XBRL DOCUMENT
v3.20.2

Income Taxes: (Details) | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2020 | Sep. 30, 2019 | Sep. 30, 2020 | Sep. 30, 2019
Golden State Water Company |  |  |  |
Effective income tax rate |  |  |  |
ETRs ( as a percent) | 26.70% | 26.40% | 25.50% | 24.10%
Parent [Member] |  |  |  |
Effective income tax rate |  |  |  |
ETRs ( as a percent) | 25.40% | 25.10% | 24.30% | 23.30%

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

X
- Definition Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 12 -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32687-109319 + Details
Name: | us-gaap_EffectiveIncomeTaxRateContinuingOperations
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

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

X
- Details
Name: | srt_ConsolidatedEntitiesAxis=us-gaap_ParentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |