Military Privatization (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Military Privatization
Billings in excess of costs and estimated earnings on contracts	$ 2,263	$ 3,764
Receivables from the U.S. government:
Less: allowance for doubtful accounts	(764)	(944)	$ (892)
Pretax income
Increase in pretax operating income	$ 114,716	118,489	119,045
Military Utility Privatization Subsidiaries
Military Privatization
Period of fixed price contracts to maintain water systems at various military bases	50 years
Initial contract period	2 years
Price redetermination interval	3 years
Revenues recognized net of billings to date
Revenues (costs and estimated earnings) recognized on uncompleted contracts	$ 104,830	111,397
Less: Billings to date	(43,161)	(61,662)
Total	61,669	49,735
Amount included in accompanying balance sheets
Costs and estimated earnings in excess of billings on uncompleted contracts	63,932	53,499
Billings in excess of costs and estimated earnings on uncompleted contracts	(2,263)	(3,764)
Total	61,669	49,735
Receivables from the U.S. government:
Billed receivables from the U.S. government	8,467	5,861
Unbilled Contract Receivables, Current	6,691	1,309
Pretax income
Government Contract Receivable	15,158	7,170
American States Utility Services [Member] | Military Utility Privatization Subsidiaries
Pretax income
Increase in pretax operating income	18,916	18,091	$ 19,351
Reportable Legal Entities [Member] | American States Utility Services [Member] | Military Utility Privatization Subsidiaries
Military Privatization
Revenue Recognition, Retrospective Rate-Setting Systems, Amount	$ 421	$ 3,000