Consolidated Statements of Comprehensive Income (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Consolidated Statements of Comprehensive Income
Net income	$ 265,021	$ 240,196	$ 132,333
Other comprehensive (loss) income:
Unrealized gains on derivatives and qualified as cash flow hedges, net of tax of $2,718 for the year ended December 31, 2011			4,751
Foreign currency translation adjustments	(1,092)	323	(747)
Other comprehensive (loss) income	(1,092)	323	4,004
Comprehensive income	$ 263,929	$ 240,519	$ 136,337