Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 233,290	$ 122,456	$ 3,279
Other comprehensive (loss) income, net of tax:
Foreign currency translation adjustments	4,169	(31,245)	47,363
Interest rate swaps - net change in deferred gain or loss	(39,394)	(10,844)	3,892
Pension plans - net change in deferred actuarial loss	(2,846)	123	(64)
Other comprehensive (loss) income, net of tax	(38,071)	(41,966)	51,191
Comprehensive income	$ 195,219	$ 80,490	$ 54,470