CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Income Statement [Abstract]
Operating revenue	$ 198,255	$ 176,174	$ 365,854	$ 325,556
Production Expenses:
Purchased water	37,421	38,129	63,374	64,321
Power	3,851	2,737	7,334	5,164
Groundwater extraction charges	26,354	17,552	44,645	29,678
Other production expenses	13,243	12,052	24,483	23,101
Total production expenses	80,869	70,470	139,836	122,264
Administrative and general	28,795	20,468	56,555	46,256
Maintenance	7,470	7,881	14,969	14,568
Property taxes and other non-income taxes	8,506	8,419	17,701	17,249
Depreciation and amortization	28,750	28,366	57,032	56,736
Total operating expense	154,390	135,604	286,093	257,073
Operating income	43,865	40,570	79,761	68,483
Other (expense) income:
Interest on long-term debt and other interest expense	(18,122)	(18,294)	(36,394)	(35,878)
Pension non-service credit	1,620	939	3,223	1,889
Other, net	1,982	1,205	2,777	3,856
Income before income taxes	29,345	24,420	49,367	38,350
Provision for income taxes	4,670	3,724	8,141	5,955
Net income	24,675	20,696	41,226	32,395
Other comprehensive loss, net	0	0	0	(442)
Comprehensive income	$ 24,675	$ 20,696	$ 41,226	$ 31,953
Earnings per share
Basic (in usd per share)	$ 0.71	$ 0.64	$ 1.20	$ 1.00
Diluted (in usd per share)	0.71	0.64	1.20	1.00
Dividends per share (in usd per share)	$ 0.42	$ 0.40	$ 0.84	$ 0.80
Weighted average shares outstanding
Basic (in shares)	34,777,152	32,397,501	34,280,727	32,237,115
Diluted (in shares)	34,860,349	32,460,894	34,367,212	32,302,741