CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 60,801	$ 64,743	$ 74,564
Other comprehensive income (loss), before tax:
Change in foreign currency translation adjustments	(19,159)	37,454	(10,278)
Unrealized gain (loss) on derivatives
Unrealized derivative (loss) gain arising during period	11,709	(3,425)	1,871
Less: Reclassification adjustments for gains included in net income	13,400	2,958	0
Unrealized (loss) gain on derivatives	(1,691)	(6,383)	1,871
Defined benefit pension plan - net (loss) gain arising during period	(643)	(57)	(45)
Total other comprehensive income (loss), before tax	(21,493)	31,014	(8,452)
Income tax benefit (expense) related to items in other comprehensive loss	(143)	2,333	(800)
Total other comprehensive income (loss), net of tax	(21,636)	33,347	(9,252)
Comprehensive income, net of tax	$ 39,165	$ 98,090	$ 65,312