CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
COMPREHENSIVE INCOME:
Net income	$ 66,358	$ 57,660	$ 185,310	$ 151,323
Foreign currency translation adjustments, net of tax	6,775	4,212	(4,486)	1,832
Total comprehensive income	$ 73,133	$ 61,872	$ 180,824	$ 153,155