Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Balance, beginning of period at Dec. 31, 2021	$ 1,526,133	$ 69,064	$ 1,781,217	$ (280,910)	$ (43,238)
Balance, beginning of period (shares) at Dec. 31, 2021		69,064,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	163,880			163,880
Shares issued for stock compensation		$ 308	(308)
Shares issued for stock compensation (shares)		308,000
Equity-based compensation expense	2,056		2,056
Pension plans and OPEB obligations, net of tax	7,480				7,480
Cash flow hedges, net of tax	43,276				43,276
Dividends on common stock	(30,524)			(30,524)
Other transactions, net	(103)		(25)	(78)
Balance, end of period at Mar. 31, 2022	1,712,198	$ 69,372	1,782,940	(147,632)	7,518
Balance, end of period (shares) at Mar. 31, 2022		69,372,000
Balance, beginning of period at Dec. 31, 2022	$ 2,263,153	$ 79,683	2,294,797	(208,979)	97,652
Balance, beginning of period (shares) at Dec. 31, 2022	79,683,000	79,683,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 16,260			16,260
Shares issued for stock compensation		$ 233	(233)
Shares issued for stock compensation (shares)		233,000
Equity-based compensation expense	2,279		2,279
Pension plans and OPEB obligations, net of tax	131				(131)
Cash flow hedges, net of tax	(17,335)				(17,335)
Dividends on common stock	(35,962)			(35,962)
Other transactions, net	(1)		84	(85)
Balance, end of period at Mar. 31, 2023	$ 2,228,263	$ 79,916	$ 2,296,927	$ (228,766)	$ 80,186
Balance, end of period (shares) at Mar. 31, 2023	79,916,000	79,916,000