Consolidated Statements of Comprehensive Income (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 284,501	$ 216,199	$ 147,335
Other comprehensive (loss) income:
Foreign currency translation adjustment (loss) gain, net of tax	(44,080)	10,370	(5,615)
Total other comprehensive (loss) income	(44,080)	10,370	(5,615)
Total comprehensive income	$ 240,421	$ 226,569	$ 141,720