Segment Information (Company's Segment Information, Continuing Operations) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Segment Reporting Information [Line Items]
Operating revenues	$ 612,069	$ 726,450
Operations and maintenance expense	136,900	137,994
Purchased gas	129,675	256,315
Depreciation and amortization	89,804	83,794
Interest expense, net	72,284	71,849
Allowance for funds used during construction	(4,681)	(5,688)
Provision for income taxes (benefit)	(10,642)	(31,637)
Net income (loss)	265,772	191,434
Capital expenditures	252,998	243,730
Regulated Water [Member] | Regulated [Member]
Segment Reporting Information [Line Items]
Operating revenues	279,894	267,300
Operations and maintenance expense	90,683	82,802
Depreciation and amortization	57,194	53,467
Interest expense, net	34,790	29,713
Allowance for funds used during construction	(3,688)	(4,946)
Provision for income taxes (benefit)	20,810	13,514
Net income (loss)	63,905	77,402
Capital expenditures	152,231	159,394
Regulated Natural Gas [Member] | Regulated [Member]
Segment Reporting Information [Line Items]
Operating revenues	324,331	441,295
Operations and maintenance expense	45,917	57,150
Purchased gas	125,542	241,856
Depreciation and amortization	32,411	30,128
Interest expense, net	25,356	27,507
Allowance for funds used during construction	(993)	(742)
Provision for income taxes (benefit)	(29,150)	(43,484)
Net income (loss)	209,940	123,546
Capital expenditures	100,767	81,669
Other [Member]
Segment Reporting Information [Line Items]
Operating revenues	7,844	17,855
Operations and maintenance expense	300	(1,958)
Purchased gas	4,133	14,459
Depreciation and amortization	199	199
Interest expense, net	12,138	14,629
Provision for income taxes (benefit)	(2,302)	(1,667)
Net income (loss)	$ (8,073)	(9,514)
Capital expenditures		$ 2,667