Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Statement of Comprehensive Income [Abstract]
Net income	$ 22,306	$ 120,222	$ 38,566	$ 284,102
Other comprehensive income (loss), net of tax:
Pension and other postretirement employee benefits	(344)	915	(475)	8,395
Cash flow hedges	17,719	42,529	384	85,805
Other comprehensive income (loss), net of tax	17,375	43,444	(91)	94,200
Comprehensive income	$ 39,681	$ 163,666	$ 38,475	$ 378,302