Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
COMPREHENSIVE INCOME:
Net income	$ 357,796	$ 305,928	$ 252,195
Foreign currency translation adjustments, net of tax	(25,024)	(23,341)	(5,708)
Total comprehensive income	$ 332,772	$ 282,587	$ 246,487