Condensed Consolidating Financial Statements (Details 3) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Condensed Consolidating Financial Statements
Operating revenue	$ 121,727	$ 121,985
Operations:
Water production costs	41,069	45,202
Administrative and general	27,827	27,695
Other operations	19,302	15,843
Maintenance	6,063	4,457
Depreciation and amortization	16,046	15,319
Income tax (benefit) expense	(925)	613
Property and other taxes	6,075	5,359
Total operating expenses	115,457	114,488
Net operating income	6,270	7,497
Other income and expenses:
Non-regulated revenue	3,428	3,247
Non-regulated expenses	(2,980)	(2,243)
Income tax (expense) on other income and expenses	(181)	(403)
Net other income	267	601
Interest expense:
Interest expense	8,065	7,069
Less: capitalized interest	(730)	(546)
Net interest expense	7,335	6,523
Equity loss of subsidiaries	0	0
Net (loss) income	(798)	1,575
Consolidating Adjustments
Condensed Consolidating Financial Statements
Operating revenue	0	0
Operations:
Water production costs	0	0
Administrative and general	0	0
Other operations	(126)	(126)
Maintenance	0	0
Depreciation and amortization	(24)	(25)
Income tax (benefit) expense	257	204
Property and other taxes	0	0
Total operating expenses	107	53
Net operating income	(107)	(53)
Other income and expenses:
Non-regulated revenue	(606)	(478)
Non-regulated expenses	0	0
Income tax (expense) on other income and expenses	247	194
Net other income	(359)	(284)
Interest expense:
Interest expense	(480)	(352)
Less: capitalized interest	0	0
Net interest expense	(480)	(352)
Equity loss of subsidiaries	937	(1,405)
Net (loss) income	951	(1,390)
Parent Company
Condensed Consolidating Financial Statements
Operating revenue	0	0
Operations:
Water production costs	0	0
Administrative and general	0	0
Other operations	0	0
Maintenance	0	0
Depreciation and amortization	57	57
Income tax (benefit) expense	(94)	(68)
Property and other taxes	0	0
Total operating expenses	(37)	(11)
Net operating income	37	11
Other income and expenses:
Non-regulated revenue	464	454
Non-regulated expenses	0	0
Income tax (expense) on other income and expenses	(189)	(185)
Net other income	275	269
Interest expense:
Interest expense	173	110
Less: capitalized interest	0	0
Net interest expense	173	110
Equity loss of subsidiaries	(937)	1,405
Net (loss) income	(798)	1,575
Cal Water
Condensed Consolidating Financial Statements
Operating revenue	113,027	114,507
Operations:
Water production costs	39,245	43,376
Administrative and general	24,943	24,855
Other operations	17,726	14,270
Maintenance	5,840	4,264
Depreciation and amortization	14,915	14,203
Income tax (benefit) expense	(1,037)	930
Property and other taxes	5,390	4,750
Total operating expenses	107,022	106,648
Net operating income	6,005	7,859
Other income and expenses:
Non-regulated revenue	3,196	2,873
Non-regulated expenses	(2,705)	(2,032)
Income tax (expense) on other income and expenses	(200)	(343)
Net other income	291	498
Interest expense:
Interest expense	7,899	6,860
Less: capitalized interest	(714)	(533)
Net interest expense	7,185	6,327
Equity loss of subsidiaries	0	0
Net (loss) income	(889)	2,030
All Other Subsidiaries
Condensed Consolidating Financial Statements
Operating revenue	8,700	7,478
Operations:
Water production costs	1,824	1,826
Administrative and general	2,884	2,840
Other operations	1,702	1,699
Maintenance	223	193
Depreciation and amortization	1,098	1,084
Income tax (benefit) expense	(51)	(453)
Property and other taxes	685	609
Total operating expenses	8,365	7,798
Net operating income	335	(320)
Other income and expenses:
Non-regulated revenue	374	398
Non-regulated expenses	(275)	(211)
Income tax (expense) on other income and expenses	(39)	(69)
Net other income	60	118
Interest expense:
Interest expense	473	451
Less: capitalized interest	(16)	(13)
Net interest expense	457	438
Equity loss of subsidiaries	0	0
Net (loss) income	$ (62)	$ (640)