STATEMENTS OF INCOME - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Regulated Operating Revenue	$ 758,320	$ 1,032,143
Cost of natural gas	383,003	665,799
Operating expenses
Operations and maintenance	132,783	126,683
Depreciation and amortization	76,572	71,264
General taxes	20,102	19,166
Total operating expenses	229,457	217,113
Operating income	145,860	149,231
Other Nonoperating Income (Expense)	3,508	2,581
Interest expense, net	(31,357)	(30,115)
Income before income taxes	118,011	121,697
Income taxes	(18,694)	(19,076)
Net income	$ 99,317	$ 102,621
Earnings per share
Basic	$ 1.75	$ 1.85
Diluted	$ 1.75	$ 1.84
Weighted Average Number of Shares Outstanding, Basic [Abstract]
Basic	56,729	55,538
Weighted Average Number of Shares Outstanding, Diluted [Abstract]
Diluted	56,800	55,800
Common Stock, Dividends, Per Share, Declared	$ 0.66	$ 0.65