Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Statement of Comprehensive Income [Abstract]
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	$ 29,071	$ 23,897	$ 55,527	$ 50,520
Other comprehensive income (loss):
Foreign currency translation adjustments	(26,178)	741	(30,937)	3,258
Total other comprehensive (loss) income	(26,178)	741	(30,937)	3,258
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	2,893	24,638	24,590	53,778
Net Income (Loss) Attributable to Noncontrolling Interest	(109)	463	139	659
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	$ 3,002	$ 24,175	$ 24,451	$ 53,119