Revenues Contract assets and Contract Liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Contract with Customer, Asset and Liability [Line Items]
Contract with Customer, Liability, Revenue Recognized	$ 7,300
Revenue, Remaining Performance Obligation, Amount	3,200,000
American States Utility Services [Member]
Contract with Customer, Asset and Liability [Line Items]
Government Contract Receivable, Unbilled Amounts	10,467	$ 5,696
Government Contract Receivable	64,819	61,126
Contract assets	15,631	24,447
Contract liabilities	$ 11,167	$ 7,530
Minimum | American States Utility Services [Member]
Contract with Customer, Asset and Liability [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	36 years
Maximum [Member] | American States Utility Services [Member]
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 [Member]
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