Condensed Consolidated Statements of Comprehensive Income (Loss) (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ (37,233)	$ 10,831	$ (112,725)	$ (126,190)
Other comprehensive income (loss), net of tax:
Interest rate swaps	1,092	(1,061)	(2,052)	(6,852)
Actuarial gain (loss)	(15)	19	(57)	49
Foreign currency translation adjustments	9,359	(3,682)	1,795	(5,514)
Total other comprehensive income (loss), net of tax	10,436	(4,724)	(314)	(12,317)
Comprehensive income (loss)	$ (26,797)	$ 6,107	$ (113,039)	$ (138,507)