CONDENSED CONSOLIDATING FINANCIAL STATEMENTS (Details 3) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Condensed Consolidating Financial Statements
Operating revenue	$ 133,700	$ 184,404	$ 154,555	$ 111,444	$ 121,530	$ 178,135	$ 143,552	$ 116,749	$ 584,103	$ 559,966	$ 501,814
Operations:
Purchased water									183,046	161,336	142,570
Purchased power									32,220	31,027	30,053
Pump taxes									10,795	10,336	9,130
Administrative and general									98,055	93,927	85,758
Other									69,738	77,104	54,696
Maintenance									17,368	19,142	20,698
Depreciation and amortization									58,320	54,668	50,385
Income tax (benefit) expense									19,047	19,356	23,025
Taxes other than income taxes									21,509	19,227	18,332
Total operating expenses									510,098	486,123	434,647
Net operating income	11,648	35,804	20,783	5,770	11,253	36,361	19,622	6,607	74,005	73,843	67,167
Other Income and Expenses:
Non-regulated revenue									14,795	16,686	16,160
Non-regulated expense									(11,265)	(11,553)	(15,822)
Gain on sale on non-utility property										84	62
Income tax (expense) on other income and expense									(1,422)	(2,096)	(141)
Net other income									2,108	3,121	259
Interest:
Interest expense									30,897	31,537	32,455
Less: capitalized interest									(2,038)	(3,401)	(2,741)
Net interest expense									28,859	28,136	29,714
Net income									47,254	48,828	37,712
Parent Company
Operations:
Administrative and general									69
Depreciation and amortization									56
Income tax (benefit) expense									(304)	(583)	(580)
Total operating expenses									(179)	(583)	(580)
Net operating income									179	583	580
Other Income and Expenses:
Non-regulated revenue									2,323	1,919	2,248
Non-regulated expense									(337)
Income tax (expense) on other income and expense									(809)	(782)	(916)
Net other income									1,177	1,137	1,332
Interest:
Interest expense									621	1,430	1,422
Net interest expense									621	1,430	1,422
Equity earnings of subsidiaries									46,519	48,538	37,222
Net income									47,254	48,828	37,712
Cal Water
Condensed Consolidating Financial Statements
Operating revenue									552,327	527,449	472,150
Operations:
Purchased water									182,503	160,913	142,355
Purchased power									22,932	21,435	20,719
Pump taxes									10,795	10,336	8,764
Administrative and general									87,620	84,399	77,622
Other									63,237	70,864	47,800
Maintenance									16,654	18,478	19,916
Depreciation and amortization									54,886	52,012	47,872
Income tax (benefit) expense									19,890	18,992	23,727
Taxes other than income taxes									18,679	16,630	15,908
Total operating expenses									477,196	454,059	404,683
Net operating income									75,131	73,390	67,467
Other Income and Expenses:
Non-regulated revenue									13,606	15,204	12,972
Non-regulated expense									(9,465)	(9,588)	(12,287)
Gain on sale on non-utility property										81	62
Income tax (expense) on other income and expense									(1,687)	(2,321)	(304)
Net other income									2,454	3,376	443
Interest:
Interest expense									30,238	30,328	31,421
Less: capitalized interest									(1,662)	(2,334)	(1,844)
Net interest expense									28,576	27,994	29,577
Net income									49,009	48,772	38,333
All Other Subsidiaries
Condensed Consolidating Financial Statements
Operating revenue									31,776	32,517	29,664
Operations:
Purchased water									543	423	215
Purchased power									9,288	9,592	9,334
Pump taxes											366
Administrative and general									10,366	9,528	8,136
Other									7,005	6,744	7,401
Maintenance									714	664	782
Depreciation and amortization									3,490	2,774	2,637
Income tax (benefit) expense									(1,880)	(375)	(1,727)
Taxes other than income taxes									2,830	2,597	2,424
Total operating expenses									32,356	31,947	29,568
Net operating income									(580)	570	96
Other Income and Expenses:
Non-regulated revenue									1,918	2,420	4,322
Non-regulated expense									(1,463)	(1,965)	(3,535)
Income tax (expense) on other income and expense									(222)	(266)	(422)
Net other income									233	189	365
Interest:
Interest expense									2,585	2,132	2,489
Less: capitalized interest									(376)	(1,067)	(897)
Net interest expense									2,209	1,065	1,592
Net income									(2,556)	(306)	(1,131)
Consolidating Adjustments
Operations:
Other									(504)	(504)	(505)
Depreciation and amortization									(112)	(118)	(124)
Income tax (benefit) expense									1,341	1,322	1,605
Total operating expenses									725	700	976
Net operating income									(725)	(700)	(976)
Other Income and Expenses:
Non-regulated revenue									(3,052)	(2,857)	(3,382)
Gain on sale on non-utility property										3
Income tax (expense) on other income and expense									1,296	1,273	1,501
Net other income									(1,756)	(1,581)	(1,881)
Interest:
Interest expense									(2,547)	(2,353)	(2,877)
Net interest expense									(2,547)	(2,353)	(2,877)
Equity earnings of subsidiaries									(46,519)	(48,538)	(37,222)
Net income									$ (46,453)	$ (48,466)	$ (37,202)