XML 22 R70.htm IDEA: XBRL DOCUMENT
v3.19.3.a.u2

Employee Benefit Plans Employee Benefit Plans 1 (Details) - Pension Benefits $ in Thousands | 12 Months Ended |
--- | --- | ---
Dec. 31, 2019 USD ($) item participant | Dec. 31, 2018 USD ($)
Employee benefit plans |  |
Defined Benefit Plan Amounts Recognized in Regulatory Asset, Liability New Prior Service Cost (Credit) | $ | $ 0 | $ 3,626
Minimum age for eligibility under the Pension Plan | item | 21 |
Minimum period of service for eligibility under the Pension Plan | 5 years |
Normal retirement benefit (as a percent) | 2.00% |
Defined Benefit Plan Number of Highest Consecutive Years Average Earnings Used in Computing Retirement Benefit | 5 years |
Maximum number of years of credited service considered in determining retirement benefit | 40 years |
Number of participants in the Pension Plan | participant | 939 |
Eligibility for employer matching contributions, period of service | 3 years |
Maximum [Member] |  |
Employee benefit plans |  |
Percentage of participant's eligible pay contributed to the plan by the employer | 5.25% |
Minimum |  |
Employee benefit plans |  |
Percentage of participant's eligible pay contributed to the plan by the employer | 3.00% |

X
- Definition Defined Benefit Plan Amounts Recognized in Regulatory Asset, Liability New Prior Service Cost (Credit) + References No definition available. + Details
Name: | awr_DefinedBenefitPlanAmountsRecognizedinRegulatoryAssetLiabilityNewPriorServiceCostCredit
Namespace Prefix: | awr_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Represents the maximum number of years of credited service used in computing the retirement benefit. + References No definition available. + Details
Name: | awr_DefinedBenefitPlanMaximumNumberOfYearsOfCreditedServiceConsideredInComputingRetirementBenefit
Namespace Prefix: | awr_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the minimum age required by the employees to be eligible to participate in the plan. + References No definition available. + Details
Name: | awr_DefinedBenefitPlanMinimumAgeForEligibility
Namespace Prefix: | awr_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the minimum period of service required in order to participate in the plan. + References No definition available. + Details
Name: | awr_DefinedBenefitPlanMinimumPeriodOfServiceForEligibility
Namespace Prefix: | awr_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the number of highest consecutive years' average earnings used in computing the retirement benefit. + References No definition available. + Details
Name: | awr_DefinedBenefitPlanNumberOfHighestConsecutiveYearsAverageEarningsUsedInComputingRetirementBenefit
Namespace Prefix: | awr_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Defined Benefit Plan, Number of Employees Covered + References No definition available. + Details
Name: | awr_DefinedBenefitPlanNumberofEmployeesCovered
Namespace Prefix: | awr_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Represents the percentage of normal retirement benefit. + References No definition available. + Details
Name: | awr_DefinedBenefitPlanRetirementBenefitPercentage
Namespace Prefix: | awr_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition The period of service required in order to be eligible for the employer's matching contributions. + References No definition available. + Details
Name: | awr_DefinedContributionPlanEligiblePeriodOfServiceForMatchingContribution
Namespace Prefix: | awr_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

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_DefinedBenefitPlanDisclosureLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of employees' gross pay for which the employer contributes a matching contribution to a defined contribution plan. + References No definition available. + Details
Name: | us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

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