CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement of Comprehensive Income [Abstract]
Net income	$ 85,436	$ 67,560	$ 63,868
Other comprehensive income (loss):
Unrealized gain on available-for-sale securities	1,488	22,977
Reclassification of unrealized gain to a realized gain on available-for-sale securities	(24,465)
Foreign currency translation adjustments	(28,716)	(19,545)	(9,284)
Total other comprehensive income (loss):	(51,693)	3,432	(9,284)
Comprehensive income	$ 33,743	$ 70,992	$ 54,584