CONDENSED CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Utility revenues:
Utility revenues, exclusive of alternative revenue programs	$ 384,214	$ 301,176	$ 862,917	$ 713,358
Alternative revenue programs	(5,793)	(3,069)	(22,570)	(2,570)
Total utility revenues	378,421	298,107	840,347	710,788
Non-utility revenues	145	148	265	337
Total operating revenues	378,566	298,255	840,612	711,125
Utility operating expenses:
Resource costs	157,397	90,678	344,265	225,257
Other operating expenses	104,482	94,053	199,009	181,608
Depreciation and amortization	62,806	56,066	125,383	111,287
Taxes other than income taxes	26,658	24,474	60,775	56,783
Non-utility operating expenses:
Other operating expenses	2,910	1,159	3,866	2,343
Depreciation and amortization	30	73	62	200
Total operating expenses	354,283	266,503	733,360	577,478
Income from operations	24,283	31,752	107,252	133,647
Interest expense	28,518	26,131	56,585	52,435
Interest expense to affiliated trusts	177	106	294	215
Capitalized interest	(932)	(916)	(2,025)	(1,931)
Other income-net	(13,934)	(10,041)	(18,785)	(13,725)
Income before income taxes	10,454	16,472	71,183	96,653
Income tax expense (benefit)	(999)	2,398	(11,835)	14,562
Net income	$ 11,453	$ 14,074	$ 83,018	$ 82,091
Weighted-average common shares outstanding (thousands), basic	72,624	69,404	72,205	69,348
Weighted-average common shares outstanding (thousands), diluted	72,658	69,534	72,294	69,520
Earnings per common share:
Basic	$ 0.16	$ 0.20	$ 1.15	$ 1.18
Diluted	$ 0.16	$ 0.20	$ 1.15	$ 1.18