CONDENSED CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Utility revenues:
Utility revenues, exclusive of alternative revenue programs	$ 478,703	$ 412,182
Alternative revenue programs	(16,777)	499
Total utility revenues	461,926	412,681
Non-utility revenues	120	189
Total operating revenues	462,046	412,870
Utility operating expenses:
Resource costs	186,868	134,579
Other operating expenses	94,527	87,555
Depreciation and amortization	62,577	55,221
Taxes other than income taxes	34,117	32,309
Non-utility operating expenses:
Other operating expenses	956	1,184
Depreciation and amortization	32	127
Total operating expenses	379,077	310,975
Income from operations	82,969	101,895
Interest expense	28,067	26,304
Interest expense to affiliated trusts	117	109
Capitalized interest	(1,093)	(1,015)
Other income-net	(4,851)	(3,684)
Income before income taxes	60,729	80,181
Income tax expense (benefit)	(10,836)	12,164
Net income	$ 71,565	$ 68,017
Weighted-average common shares outstanding (thousands), basic	71,787	69,293
Weighted-average common shares outstanding (thousands), diluted	71,930	69,506
Earnings per common share:
Basic	$ 1.00	$ 0.98
Diluted	$ 0.99	$ 0.98