STATEMENTS OF INCOME - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Regulated Operating Revenue	$ 340,398	$ 335,816	$ 1,452,855	$ 1,766,073
Cost of natural gas	59,632	70,910	514,593	866,950
Operating expenses
Operations and maintenance	130,743	121,623	385,258	366,921
Depreciation and amortization	72,126	68,435	221,247	207,246
General taxes	18,448	17,645	57,023	54,501
Total operating expenses	221,317	207,703	663,528	628,668
Operating income	59,449	57,203	274,734	270,455
Other Nonoperating Income (Expense)	2,982	55	7,322	4,810
Interest expense, net	(39,148)	(27,961)	(107,475)	(85,561)
Income before income taxes	23,283	29,297	174,581	189,704
Income taxes	(4,015)	(4,108)	(28,753)	(29,205)
Net income	$ 19,268	$ 25,189	$ 145,828	$ 160,499
Earnings per share
Basic	$ 0.34	$ 0.45	$ 2.57	$ 2.89
Diluted	$ 0.34	$ 0.45	$ 2.56	$ 2.87
Weighted Average Number of Shares Outstanding, Basic [Abstract]
Basic	56,825	55,624	56,768	55,576
Weighted Average Number of Shares Outstanding, Diluted [Abstract]
Diluted	57,093	55,975	56,906	55,897
Common Stock, Dividends, Per Share, Declared	$ 0.66	$ 0.65	$ 1.98	$ 1.95