CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Income Statement [Abstract]
Operating revenue	$ 206,194	$ 213,123	$ 379,187	$ 360,860
Operations:
Water production costs	70,907	74,911	132,445	129,737
Administrative and general	32,686	31,756	66,097	62,125
Other operations	29,417	20,720	55,269	38,632
Maintenance	7,615	6,610	14,956	13,379
Depreciation and amortization	28,773	27,237	57,543	54,284
Income taxes	1,454	1,972	37	1,871
Property and other taxes	8,053	7,671	16,413	15,667
Total operating expenses	178,905	170,877	342,760	315,695
Net operating income	27,289	42,246	36,427	45,165
Other income and expenses:
Non-regulated revenue	7,002	5,374	12,199	10,946
Non-regulated expenses	(8,541)	(1,815)	(15,527)	(6,575)
Other components of net periodic benefit credit	3,765	2,688	7,779	5,667
Allowance for equity funds used during construction	1,042	848	2,017	1,392
Income tax expense on other income and expenses	(345)	(512)	(857)	(870)
Net other income	2,923	6,583	5,611	10,560
Interest expense:
Interest expense	11,586	11,206	23,081	21,428
Allowance for borrowed funds used during construction	(589)	(453)	(1,152)	(747)
Net interest expense	10,997	10,753	21,929	20,681
Net income	19,215	38,076	20,109	35,044
Net loss attributable to noncontrolling interests	(269)	(149)	(461)	(149)
Net income attributable to California Water Service Group	$ 19,484	$ 38,225	$ 20,570	$ 35,193
Earnings per share of common stock:
Basic (in dollars per share)	$ 0.36	$ 0.75	$ 0.38	$ 0.69
Diluted (in dollars per share)	$ 0.36	$ 0.75	$ 0.38	$ 0.69
Weighted average shares outstanding:
Basic (in shares)	54,007	51,080	53,870	50,762
Diluted (in shares)	54,042	51,080	53,918	50,762