Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Statement of Comprehensive Income [Abstract]
Net income	$ 271,236	$ 55,077	$ 435,336	$ 130,174
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments	4,639	23,817	5,316	(22,564)
Interest rate swaps – net change in deferred gain or loss	5,457	2,900	10,727	(41,832)
Pension plans – net change in deferred actuarial loss	104	80	207	159
Other comprehensive income (loss), net of tax	10,200	26,797	16,250	(64,237)
Comprehensive income	$ 281,436	$ 81,874	$ 451,586	$ 65,937