Revenues Contract assets and Contract Liabilities (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($) unit	Dec. 31, 2022 USD ($)
Contract with Customer, Asset and Liability [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 4,000,000
American States Utility Services
Contract with Customer, Asset and Liability [Line Items]
Unbilled Contracts Receivable	9,693	$ 10,125
Government Contract Receivable	91,489	85,456
Contract assets	14,378	14,982
Contract liabilities	$ 1,352	$ 903
Minimum | American States Utility Services
Contract with Customer, Asset and Liability [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	15 years
Maximum | American States Utility Services
Contract with Customer, Asset and Liability [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	50 years
Contracted services: | American States Utility Services
Contract with Customer, Asset and Liability [Line Items]
Number of the contracts with 15-year contracts with the U.S. government | unit	1
Contracted services: | Minimum | American States Utility Services
Contract with Customer, Asset and Liability [Line Items]
Period of Fixed Price Contracts to Operate and Maintain Water Systems at Various Military Bases	15 years
Contracted services: | Maximum
Contract with Customer, Asset and Liability [Line Items]
Period of Fixed Price Contracts to Operate and Maintain Water Systems at Various Military Bases	50 years
Contracted services: | Maximum | American States Utility Services
Contract with Customer, Asset and Liability [Line Items]
Period of Fixed Price Contracts to Operate and Maintain Water Systems at Various Military Bases	50 years