SCHEDULE I - CONDENSED FINANCIAL INFORMATION OF PARENT (Details 3) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Condensed statement of cash flows
Cash Flows From Operating Activities	$ 101,494,000	$ 80,167,000	$ 53,764,000
Cash Flows From Investing Activities:
Proceeds from the sale of CCWC		29,603,000
Net cash used	(68,036,000)	(50,534,000)	(78,230,000)
Cash Flows From Financing Activities:
Proceeds from the issuance of common stock		1,658,000	1,838,000
Proceeds from stock option exercises	13,295,000	2,350,000	857,000
Net change in notes payable to banks	(2,000,000)	(58,900,000)	43,500,000
Dividends paid	(24,130,000)	(20,552,000)	(19,326,000)
Net cash provided (used)	(11,287,000)	(32,515,000)	28,275,000
Net increase (decrease) in cash and cash equivalents	22,171,000	(2,882,000)	3,809,000
Cash and cash equivalents, beginning of year	1,315,000	5,494,000	1,685,000
Cash and cash equivalents, end of year	23,486,000	1,315,000	5,494,000
AWR
Condensed statement of cash flows
Cash Flows From Operating Activities	16,885,000	17,945,000	17,627,000
Cash Flows From Investing Activities:
Loans (made to)/repaid from, wholly-owned subsidiaries	(4,720,000)	36,786,000	(22,475,000)
Increase in investment of subsidiary		(10,000,000)	(20,000,000)
Proceeds from the sale of CCWC		29,603,000
Net cash used	(4,720,000)	56,389,000	(42,475,000)
Cash Flows From Financing Activities:
Proceeds from the issuance of common stock		1,658,000	1,838,000
Proceeds from stock option exercises	13,295,000	2,350,000	857,000
Net change in notes payable to banks	(2,000,000)	(58,900,000)	43,500,000
Dividends paid	(24,130,000)	(20,552,000)	(19,326,000)
Net cash provided (used)	(12,835,000)	(75,444,000)	26,869,000
Net increase (decrease) in cash and cash equivalents	(670,000)	(1,110,000)	2,021,000
Cash and cash equivalents, beginning of year	981,000	2,091,000	70,000
Cash and cash equivalents, end of year	$ 311,000	$ 981,000	$ 2,091,000