Condensed Consolidating Financial Statements (Details 3) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Condensed Consolidating Financial Statements
Operating revenue	$ 184,268	$ 183,543	$ 458,440	$ 449,942
Operations:
Water production costs	70,175	60,437	168,833	158,661
Administrative and general	23,844	30,737	75,037	85,069
Other operations	19,561	17,872	57,766	51,227
Maintenance	5,545	5,952	17,542	15,735
Depreciation and amortization	15,884	15,342	47,772	46,015
Income tax (benefit) expense	13,247	15,293	19,192	21,008
Property and other taxes	5,957	5,709	17,439	16,036
Total operating (income) expense	154,213	151,342	403,581	393,751
Net operating income (loss)	30,055	32,201	54,859	56,191
Other income and expenses:
Non-regulated revenue	3,397	3,814	10,589	10,540
Non-regulated expenses	(2,517)	(4,454)	(8,306)	(10,201)
Income tax (expense) benefit on other income and expenses	(349)	262	(914)	(131)
Net other income (loss)	531	(378)	1,369	208
Interest:
Interest expense	8,485	7,201	24,984	21,331
Less: capitalized interest	(774)	(498)	(2,341)	(1,472)
Net interest expense	7,711	6,703	22,643	19,859
Equity earnings of subsidiaries	0	0	0	0
Net income	22,875	25,120	33,585	36,540
Consolidating Adjustments
Condensed Consolidating Financial Statements
Operating revenue	0	0	0	0
Operations:
Water production costs	0	0	0	0
Administrative and general	0	0	0	0
Other operations	(168)	(125)	(378)	(378)
Maintenance	0	0	0	0
Depreciation and amortization	(24)	(25)	(72)	(76)
Income tax (benefit) expense	267	254	762	756
Property and other taxes	0	0	0	0
Total operating (income) expense	75	104	312	302
Net operating income (loss)	(75)	(104)	(312)	(302)
Other income and expenses:
Non-regulated revenue	(632)	(570)	(1,798)	(1,728)
Non-regulated expenses	0	0	0	0
Income tax (expense) benefit on other income and expenses	258	244	733	725
Net other income (loss)	(374)	(326)	(1,065)	(1,003)
Interest:
Interest expense	(463)	(445)	(1,419)	(1,350)
Less: capitalized interest	0	0	0	0
Net interest expense	(463)	(445)	(1,419)	(1,350)
Equity earnings of subsidiaries	(22,753)	(25,012)	(33,187)	(36,168)
Net income	(22,739)	(24,997)	(33,145)	(36,123)
Parent Company
Condensed Consolidating Financial Statements
Operating revenue	0	0	0	0
Operations:
Water production costs	0	0	0	0
Administrative and general	0	0	0	0
Other operations	0	0	0	0
Maintenance	0	0	0	0
Depreciation and amortization	57	57	171	171
Income tax (benefit) expense	(105)	(107)	(292)	(294)
Property and other taxes	0	0	0	0
Total operating (income) expense	(48)	(50)	(121)	(123)
Net operating income (loss)	48	50	121	123
Other income and expenses:
Non-regulated revenue	464	444	1,390	1,353
Non-regulated expenses	0	0	0	0
Income tax (expense) benefit on other income and expenses	(189)	(181)	(566)	(549)
Net other income (loss)	275	263	824	804
Interest:
Interest expense	201	205	547	555
Less: capitalized interest	0	0	0	0
Net interest expense	201	205	547	555
Equity earnings of subsidiaries	22,753	25,012	33,187	36,168
Net income	22,875	25,120	33,585	36,540
Cal Water
Condensed Consolidating Financial Statements
Operating revenue	173,223	172,425	428,592	422,372
Operations:
Water production costs	68,045	58,173	162,933	152,593
Administrative and general	21,679	27,620	67,289	76,271
Other operations	18,037	16,329	53,128	46,632
Maintenance	5,322	5,722	16,854	15,148
Depreciation and amortization	14,777	14,231	44,427	42,659
Income tax (benefit) expense	12,165	14,638	17,356	20,454
Property and other taxes	5,182	4,910	15,241	13,964
Total operating (income) expense	145,207	141,623	377,228	367,721
Net operating income (loss)	28,016	30,802	51,364	54,651
Other income and expenses:
Non-regulated revenue	3,024	3,489	9,659	9,674
Non-regulated expenses	(2,170)	(4,058)	(7,422)	(9,283)
Income tax (expense) benefit on other income and expenses	(345)	232	(909)	(159)
Net other income (loss)	509	(337)	1,328	232
Interest:
Interest expense	8,259	6,969	24,421	20,751
Less: capitalized interest	(759)	(488)	(2,293)	(1,438)
Net interest expense	7,500	6,481	22,128	19,313
Equity earnings of subsidiaries	0	0	0	0
Net income	21,025	23,984	30,564	35,570
All Other Subsidiaries
Condensed Consolidating Financial Statements
Operating revenue	11,045	11,118	29,848	27,570
Operations:
Water production costs	2,130	2,264	5,900	6,068
Administrative and general	2,165	3,117	7,748	8,798
Other operations	1,692	1,668	5,016	4,973
Maintenance	223	230	688	587
Depreciation and amortization	1,074	1,079	3,246	3,261
Income tax (benefit) expense	920	508	1,366	92
Property and other taxes	775	799	2,198	2,072
Total operating (income) expense	8,979	9,665	26,162	25,851
Net operating income (loss)	2,066	1,453	3,686	1,719
Other income and expenses:
Non-regulated revenue	541	451	1,338	1,241
Non-regulated expenses	(347)	(396)	(884)	(918)
Income tax (expense) benefit on other income and expenses	(73)	(33)	(172)	(148)
Net other income (loss)	121	22	282	175
Interest:
Interest expense	488	472	1,435	1,375
Less: capitalized interest	(15)	(10)	(48)	(34)
Net interest expense	473	462	1,387	1,341
Equity earnings of subsidiaries	0	0	0	0
Net income	$ 1,714	$ 1,013	$ 2,581	$ 553