CONDENSED CONSOLIDATING FINANCIAL STATEMENTS (Details 2) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Utility plant:
Utility plant	$ 2,213,328	$ 2,096,363
Less accumulated depreciation and amortization	(697,497)	(639,307)
Net utility plant	1,515,831	1,457,056
Current assets:
Cash and cash equivalents	27,506	38,790	27,203	42,277
Receivables	98,089	91,315
Other current assets	13,895	16,459
Total current assets	139,490	146,564
Other assets:
Regulatory assets	251,681	344,419
Other assets	52,853	47,885
Total other assets	304,534	392,304
Total assets	1,959,855	1,995,924
Capitalization:
Common stockholders' equity	598,756	473,712	449,829	435,526
Long-term debt, less current maturities	426,142	434,467
Total capitalization	1,024,898	908,179
Current liabilities:
Current maturities of long-term debt	7,908	46,783
Short-term borrowings	46,815	89,475
Accounts payable	55,087	47,199
Accrued expenses and other liabilities	56,774	59,610
Total current liabilities	166,584	243,067
Unamortized investment tax credits	2,106	2,180
Deferred income taxes, net	183,245	158,846
Pension and postretirement benefits other than pensions	145,451	244,901
Regulatory and other liabilities	86,455	92,593
Advances for construction	183,393	187,584
Contributions in aid of construction	167,723	158,574
Total capitalization and liabilities	1,959,855	1,995,924
Parent Company
Utility plant:
Utility plant	1,318	606
Less accumulated depreciation and amortization	(164)	(108)
Net utility plant	1,154	498
Current assets:
Cash and cash equivalents	5,280	1,470	89	188
Receivables	(756)
Receivables from affiliates	16,747	19,367
Total current assets	21,271	20,837
Other assets:
Investments in affiliates	565,347	492,188
Long-term affiliate notes receivable	26,255	31,218
Other assets	1,120	1,023
Total other assets	592,722	524,429
Total assets	615,147	545,764
Capitalization:
Common stockholders' equity	598,756	473,712
Affiliate long-term debt		7,781
Total capitalization	598,756	481,493
Current liabilities:
Short-term borrowings	16,815	64,475
Payables to affiliates	48	77
Accrued expenses and other liabilities	107	298
Total current liabilities	16,970	64,850
Deferred income taxes, net	(579)	(579)
Total capitalization and liabilities	615,147	545,764
Cal Water
Utility plant:
Utility plant	2,034,935	1,927,190
Less accumulated depreciation and amortization	(661,780)	(607,992)
Net utility plant	1,373,155	1,319,198
Current assets:
Cash and cash equivalents	20,790	34,609	18,475	40,446
Receivables	90,008	87,482
Receivables from affiliates	5,755	3,195
Other current assets	13,011	15,535
Total current assets	129,564	140,821
Other assets:
Regulatory assets	248,938	341,877
Long-term affiliate notes receivable		7,781
Other assets	44,827	40,005
Total other assets	293,765	389,663
Total assets	1,796,484	1,849,682
Capitalization:
Common stockholders' equity	500,290	442,923
Long-term debt, less current maturities	424,854	431,433
Total capitalization	925,144	874,356
Current liabilities:
Current maturities of long-term debt	6,137	46,104
Short-term borrowings	30,000	25,000
Payables to affiliates		1,152
Accounts payable	51,764	41,352
Accrued expenses and other liabilities	55,346	58,293
Total current liabilities	143,247	171,901
Unamortized investment tax credits	2,106	2,180
Deferred income taxes, net	179,870	155,481
Pension and postretirement benefits other than pensions	145,451	244,901
Regulatory and other liabilities	77,627	83,942
Advances for construction	182,776	186,753
Contributions in aid of construction	140,263	130,168
Total capitalization and liabilities	1,796,484	1,849,682
All Other Subsidiaries
Utility plant:
Utility plant	184,272	175,764
Less accumulated depreciation and amortization	(37,168)	(32,710)
Net utility plant	147,104	143,054
Current assets:
Cash and cash equivalents	1,436	2,711	8,639	1,643
Receivables	8,931	3,833
Receivables from affiliates		1,152
Other current assets	884	924
Total current assets	11,251	8,620
Other assets:
Regulatory assets	2,743	2,542
Other assets	7,111	7,062
Total other assets	9,854	9,604
Total assets	168,209	161,278
Capitalization:
Common stockholders' equity	70,548	54,774
Affiliate long-term debt	26,255	31,218
Long-term debt, less current maturities	1,288	3,034
Total capitalization	98,091	89,026
Current liabilities:
Current maturities of long-term debt	1,771	679
Payables to affiliates	22,454	22,485
Accounts payable	3,323	5,847
Accrued expenses and other liabilities	1,321	1,019
Total current liabilities	28,869	30,030
Deferred income taxes, net	4,344	4,334
Regulatory and other liabilities	8,828	8,651
Advances for construction	617	831
Contributions in aid of construction	27,460	28,406
Total capitalization and liabilities	168,209	161,278
Consolidating Adjustments
Utility plant:
Utility plant	(7,197)	(7,197)
Less accumulated depreciation and amortization	1,615	1,503
Net utility plant	(5,582)	(5,694)
Current assets:
Receivables	(94)
Receivables from affiliates	(22,502)	(23,714)
Total current assets	(22,596)	(23,714)
Other assets:
Investments in affiliates	(565,347)	(492,188)
Long-term affiliate notes receivable	(26,255)	(38,999)
Other assets	(205)	(205)
Total other assets	(591,807)	(531,392)
Total assets	(619,985)	(560,800)
Capitalization:
Common stockholders' equity	(570,838)	(497,697)
Affiliate long-term debt	(26,255)	(38,999)
Total capitalization	(597,093)	(536,696)
Current liabilities:
Payables to affiliates	(22,502)	(23,714)
Total current liabilities	(22,502)	(23,714)
Deferred income taxes, net	(390)	(390)
Total capitalization and liabilities	$ (619,985)	$ (560,800)