CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Utility revenues:
Utility revenues, exclusive of alternative revenue programs	$ 1,746,097	$ 1,742,876	$ 1,445,000
Alternative revenue programs	4,899	(33,357)	(6,635)
Total utility revenues	1,750,996	1,709,519	1,438,365
Non-utility revenues	558	688	571
Total operating revenues	1,751,554	1,710,207	1,438,936
Utility operating expenses:
Resource costs	702,372	735,862	497,123
Other operating expenses	413,608	405,165	366,125
Depreciation and amortization	265,329	253,017	231,915
Taxes other than income taxes	109,715	114,193	109,353
Non-utility operating expenses	2,840	11,728	6,188
Total operating expenses	1,493,864	1,519,965	1,210,704
Income from operations	257,690	190,242	228,232
Interest expense	140,795	117,634	105,731
Interest expense to affiliated trust	2,504	1,058	421
Capitalized interest	(3,633)	(3,718)	(3,987)
Other income-net	(19,526)	(62,717)	(33,298)
Income before income taxes	137,550	137,985	159,365
Income tax expense (benefit)	(33,630)	(17,191)	12,031
Net income	$ 171,180	$ 155,176	$ 147,334
Weighted-average common shares outstanding (thousands), basic	76,396	72,989	69,951
Weighted-average common shares outstanding (thousands), diluted	76,495	73,093	70,085
Earnings per common share:
Basic	$ 2.24	$ 2.13	$ 2.11
Diluted	$ 2.24	$ 2.12	$ 2.1