XML 33 R20.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Derivative Instruments (Tables) | 6 Months Ended
--- | ---
Jun. 30, 2018
GOLDEN STATE WATER COMPANY |
Derivative Instruments, Gain (Loss) [Line Items] |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation | The following table presents changes in the fair value of GSWC’s Level 3 derivatives for the three and six months ended June 30, 2018 and 2017:
|  | For The Three Months Ended June 30, |  | For The Six Months Ended June 30,
(dollars in thousands) |  | 2018 |  | 2017 |  | 2018 |  | 2017
Fair value at beginning of the period |  | $ | (2,625 | ) |  | $ | (5,460 | ) |  | $ | (2,941 | ) |  | $ | (4,901 | )
Unrealized gain on purchased power contracts |  | 915 |  |  | 967 |  |  | 1,231 |  |  | 408 |
Fair value at end of the period |  | $ | (1,710 | ) |  | $ | (4,493 | ) |  | $ | (1,710 | ) |  | $ | (4,493 | )

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

X
- Definition Tabular disclosure of financial instrument classified as a derivative asset (liability) after deduction of derivative liability (asset) using recurring unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19279-110258 + Details
Name: | us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputReconciliationTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

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