CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Statement of Comprehensive Income [Abstract]
Net income	$ 36,137	$ 39,213	$ 72,906	$ 92,877
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments	(20,087)	21,841	(21,352)	(10,693)
Total comprehensive income	$ 16,050	$ 61,054	$ 51,554	$ 82,184