CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Income Statement [Abstract]
Operating revenue	$ 244,299	$ 194,044	$ 515,048	$ 325,144
Operations:
Water production costs	77,644	70,867	141,829	125,875
Administrative and general	32,042	34,975	67,638	70,961
Other operations	25,626	25,823	52,551	42,427
Maintenance	8,790	7,155	16,800	15,133
Depreciation and amortization	32,978	29,824	65,822	59,739
Income tax expense (benefit)	8,689	329	24,227	(5,315)
Property and other taxes	10,364	9,122	20,121	17,899
Total operating expenses	196,133	178,095	388,988	326,719
Net operating income (loss)	48,166	15,949	126,060	(1,575)
Other income and expenses:
Non-regulated revenue	5,513	4,485	10,611	9,108
Non-regulated expenses	(4,125)	(2,957)	(6,079)	(5,232)
Other components of net periodic benefit credit	4,338	4,756	7,611	9,977
Allowance for equity funds used during construction	1,819	1,355	3,561	2,759
Income tax expense on other income and expenses	(1,306)	(1,445)	(2,627)	(3,239)
Net other income	6,239	6,194	13,077	13,373
Interest expense:
Interest expense	14,840	13,491	30,640	26,309
Allowance for borrowed funds used during construction	(812)	(795)	(1,570)	(1,624)
Net interest expense	14,028	12,696	29,070	24,685
Net income (loss)	40,377	9,447	110,067	(12,887)
Net loss attributable to noncontrolling interests	(174)	(109)	(401)	(232)
Net income (loss) attributable to California Water Service Group	$ 40,551	$ 9,556	$ 110,468	$ (12,655)
Earnings (loss) per share:
Basic (in dollars per share)	$ 0.70	$ 0.17	$ 1.90	$ (0.23)
Diluted (in dollars per share)	$ 0.70	$ 0.17	$ 1.90	$ (0.23)
Weighted average shares outstanding:
Basic (in shares)	58,292	56,692	58,013	56,182
Diluted (in shares)	58,325	56,730	58,046	56,182