SCHEDULE I - CONDENSED FINANCIAL INFORMATION OF PARENT 3 (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash Flows From Financing Activities:
Payments for Repurchase of Common Stock	$ 0	$ 0	$ (72,893)
Proceeds from stock option exercises	909	235	1,198
Net change in notes payable to banks	(31,000)	62,000	28,000
Dividends paid	(36,417)	(33,408)	(32,690)
Proceeds from (Payments for) Other Financing Activities	(1,292)	(1,490)	(957)
Net increase (decrease) in cash and cash equivalents	(222)	(3,928)	(71,624)
Cash and cash equivalents, beginning of year	436	4,364	75,988
Cash and cash equivalents, end of year	214	436	4,364
AWR
Condensed financial statements
Cash Flows From Operating Activities	36,024	34,878	57,682
Cash Flows From Investing Activities:
Loans (made to)/repaid from, wholly-owned subsidiaries	30,500	(64,500)	(12,000)
Net cash used	30,500	(64,500)	(12,000)
Cash Flows From Financing Activities:
Payments for Repurchase of Common Stock	0	0	(72,893)
Proceeds from note payable to GSWC	0	0	20,700
Repayment of note payable to GSWC	0	0	(20,700)
Proceeds from stock option exercises	909	235	1,198
Net change in notes payable to banks	(31,000)	62,000	28,000
Dividends paid	(36,417)	(33,408)	(32,690)
Proceeds from (Payments for) Other Financing Activities	0	(9)	(90)
Net cash provided (used)	(66,508)	28,818	(76,475)
Net increase (decrease) in cash and cash equivalents	16	(804)	(30,793)
Cash and cash equivalents, beginning of year	32	836	31,629
Cash and cash equivalents, end of year	$ 48	$ 32	$ 836