Segment Information (Company's Segment Information, Continuing Operations) (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2023	Jun. 30, 2022
Segment Reporting Information [Line Items]
Operating revenues	$ 436,700		$ 448,756		$ 1,163,150	$ 1,148,031
Operations and maintenance expense	133,508		134,981		271,502	277,562
Purchased gas	41,933		75,143		298,248	302,855
Depreciation and amortization	85,661		79,176		169,455	157,522
Interest expense, net	68,212		54,397		140,061	107,424
Allowance for funds used during construction	(3,424)		(6,151)		(9,112)	(11,990)
Provision for income taxes (benefit)	(263)		8,100		(31,900)	(9,133)
Net income (loss)	91,268	$ 191,434	82,291	$ 199,376	282,702	281,667
Capital expenditures					547,600	424,645
Water [Member] | Regulated [Member]
Segment Reporting Information [Line Items]
Operating revenues	293,672		269,355		560,972	508,553
Operations and maintenance expense	93,227		92,815		176,029	178,903
Depreciation and amortization	53,231		50,260		106,698	98,976
Interest expense, net	30,523		27,604		60,236	55,159
Allowance for funds used during construction	(2,940)		(5,347)		(7,886)	(10,496)
Provision for income taxes (benefit)	15,859		13,847		29,373	21,346
Net income (loss)	90,027		76,342		167,429	136,885
Capital expenditures					329,862	216,612
Natural Gas [Member] | Regulated [Member]
Segment Reporting Information [Line Items]
Operating revenues	138,983		167,729		580,278	612,912
Operations and maintenance expense	41,114		44,907		98,264	104,359
Purchased gas	39,665		63,392		281,521	280,698
Depreciation and amortization	32,188		29,131		62,316	58,835
Interest expense, net	20,982		19,171		48,489	39,823
Allowance for funds used during construction	(484)		(804)		(1,226)	(1,493)
Provision for income taxes (benefit)	(13,314)		(5,170)		(56,798)	(31,645)
Net income (loss)	13,630		11,478		137,176	150,964
Capital expenditures					215,212	207,394
Other [Member]
Segment Reporting Information [Line Items]
Operating revenues	4,045		11,672		21,900	26,566
Operations and maintenance expense	(833)		(2,741)		(2,791)	(5,700)
Purchased gas	2,268		11,751		16,727	22,157
Depreciation and amortization	242		(215)		441	(289)
Interest expense, net	16,707		7,622		31,336	12,442
Allowance for funds used during construction						(1)
Provision for income taxes (benefit)	(2,808)		(577)		(4,475)	1,166
Net income (loss)	$ (12,389)		$ (5,529)		(21,903)	(6,182)
Capital expenditures					$ 2,526	$ 639