Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Statement of Comprehensive Income [Abstract]
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	$ 23,897	$ 23,043	$ 50,520	$ 45,394
Other comprehensive income (loss):
Foreign currency translation adjustments	741	(2,122)	3,258	(465)
Total other comprehensive income (loss)	741	(2,122)	3,258	(465)
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	24,638	20,921	53,778	44,929
Net Income (Loss) Attributable to Noncontrolling Interest	463	51	659	243
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	$ 24,175	$ 20,870	$ 53,119	$ 44,686