Condensed Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Statement of Comprehensive Income [Abstract]
Net income	$ 164,100	$ 75,097
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments	677	(46,381)
Interest rate swaps – net change in deferred gain or loss	5,270	(44,732)
Pension plans – net change in deferred actuarial loss	103	79
Other comprehensive income (loss), net of tax	6,050	(91,034)
Comprehensive income (loss)	$ 170,150	$ (15,937)