STATEMENTS OF INCOME - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Regulated Operating Revenue	$ 935,190	$ 758,320
Cost of natural gas	512,462	383,003
Operating expenses
Operations and maintenance	135,295	132,783
Depreciation and amortization	81,704	76,572
General taxes	25,230	20,102
Total operating expenses	242,229	229,457
Operating income	180,499	145,860
Other Nonoperating Income (Expense)	518	3,508
Interest expense, net	(35,697)	(31,357)
Income before income taxes	145,320	118,011
Income taxes	(25,901)	(18,694)
Net income	$ 119,419	$ 99,317
Earnings per share
Basic	$ 1.99	$ 1.75
Diluted	$ 1.98	$ 1.75
Weighted Average Number of Shares Outstanding, Basic [Abstract]
Basic	60,077	56,729
Weighted Average Number of Shares Outstanding, Diluted [Abstract]
Diluted	60,266	56,800
Common Stock, Dividends, Per Share, Declared	$ 0.67	$ 0.66