Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Statement of Comprehensive Income [Abstract]
Net income	$ 120,222	$ 187,905	$ 284,102	$ 319,011
Other comprehensive income (loss), net of tax:
Net loss arising during the period, net of tax benefit of $0, $0, $1,570 and $0	0	0	(4,587)	0
Effect of pension settlement, net of tax expense of $0, $0, $3,612 and $0	0	0	10,553	0
Amortization of actuarial loss included in net income, net of tax expense of $267, $1,073, $742 and $2,182	786	3,050	2,170	6,207
Amortization of prior service cost (credit) included in net income, net of tax expense (benefit) of $45, $(72), $89 and $(145)	129	(205)	259	(409)
Cash flow hedges, net of tax expense (benefit) of $2,817, $(2,179), $5,066 and $1,853	42,529	(31,163)	85,805	32,944
Other comprehensive income (loss), net of tax	43,444	(28,318)	94,200	38,742
Comprehensive income	$ 163,666	$ 159,587	$ 378,302	$ 357,753