Condensed Consolidated Statements of Comprehensive (Loss) Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Statement of Comprehensive Income [Abstract]
Net (loss) income	$ (48,180)	$ 30,484	$ (104,028)	$ 127,097
Other comprehensive (loss) income, net of tax:
Foreign currency translation adjustments	46,319	(3,032)	51,714	2,371
Interest rate swaps – net change in deferred loss	1,302	3,214	(3,396)	(5,865)
Pension – net change in deferred actuarial loss	52	37	149	112
Other comprehensive (loss) income, net of tax	47,673	219	48,467	(3,382)
Comprehensive (loss) income	$ (507)	$ 30,703	$ (55,561)	$ 123,715