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 [Member]
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
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
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
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	38,566
Cash flow hedges, net of tax	384
Balance, end of period at Jun. 30, 2023	2,233,169	$ 79,911	2,298,593	(242,896)	97,561
Balance, end of period (shares) at Jun. 30, 2023		79,911,000
Balance, beginning of period at Mar. 31, 2023	2,228,263	$ 79,916	2,296,927	(228,766)	80,186
Balance, beginning of period (shares) at Mar. 31, 2023		79,916,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	22,306			22,306
Shares issued for stock compensation		$ 4	(4)
Shares issued for stock compensation (shares)		4,000
Equity-based compensation expense	1,577		1,577
Repurchase of common stock	(394)	$ (9)		(385)
Repurchase of common stock (shares)		(9,000)
Pension plans and OPEB obligations, net of tax	(344)				(344)
Cash flow hedges, net of tax	17,719				17,719
Dividends on common stock	(35,958)			(35,958)
Other transactions, net			93	(93)
Balance, end of period at Jun. 30, 2023	2,233,169	$ 79,911	2,298,593	(242,896)	97,561
Balance, end of period (shares) at Jun. 30, 2023		79,911,000
Balance, beginning of period at Dec. 31, 2023	$ 2,171,098	$ 79,365	2,303,992	(315,291)	103,032
Balance, beginning of period (shares) at Dec. 31, 2023	79,365,000	79,365,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ (305)			(305)
Shares issued for stock compensation		$ 143	(143)
Shares issued for stock compensation (shares)		143,000
Equity-based compensation expense	2,560		2,560
Pension plans and OPEB obligations, net of tax	(229)				(229)
Cash flow hedges, net of tax	15,925				15,925
Dividends on common stock	(35,779)			(35,779)
Other transactions, net	2		90	(88)
Balance, end of period at Mar. 31, 2024	2,153,272	$ 79,508	2,306,499	(351,463)	118,728
Balance, end of period (shares) at Mar. 31, 2024		79,508,000
Balance, beginning of period at Dec. 31, 2023	$ 2,171,098	$ 79,365	2,303,992	(315,291)	103,032
Balance, beginning of period (shares) at Dec. 31, 2023	79,365,000	79,365,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 13,373
Cash flow hedges, net of tax	19,536
Balance, end of period at Jun. 30, 2024	$ 2,112,599	$ 78,902	2,309,555	(397,967)	122,109
Balance, end of period (shares) at Jun. 30, 2024	78,902,000	78,902,000
Balance, beginning of period at Mar. 31, 2024	$ 2,153,272	$ 79,508	2,306,499	(351,463)	118,728
Balance, beginning of period (shares) at Mar. 31, 2024		79,508,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	13,678			13,678
Shares issued for stock compensation		$ 4	(4)
Shares issued for stock compensation (shares)		4,000
Equity-based compensation expense	2,962		2,962
Repurchase of common stock	(25,012)	$ (610)		(24,402)
Repurchase of common stock (shares)		(610,000)
Pension plans and OPEB obligations, net of tax	(230)				(230)
Cash flow hedges, net of tax	3,611				3,611
Dividends on common stock	(35,677)			(35,677)
Other transactions, net	(5)		98	(103)
Balance, end of period at Jun. 30, 2024	$ 2,112,599	$ 78,902	$ 2,309,555	$ (397,967)	$ 122,109
Balance, end of period (shares) at Jun. 30, 2024	78,902,000	78,902,000