Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Statement of Comprehensive Income [Abstract]
Net income	$ 148,865	$ 16,964	$ 584,201	$ 147,138
Other comprehensive (loss) income, net of tax:
Foreign currency translation adjustments	(6,488)	7,498	(1,172)	(15,066)
Interest rate swaps – net change in deferred gain or loss	5,529	4,379	16,256	(37,453)
Pension plans – net change in deferred actuarial loss	100	85	307	244
Other comprehensive (loss) income, net of tax	(859)	11,962	15,391	(52,275)
Comprehensive income	$ 148,006	$ 28,926	$ 599,592	$ 94,863