Consolidated Statements of Comprehensive Income (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Components of Comprehensive Income
Net income	$ 670,292	$ 585,746	$ 507,673
Reclassification adjustment for unrealized losses on cash flow hedges, net of tax, included in net income	0	0	2,970
Other comprehensive income	0	0	2,970
Total comprehensive income	$ 670,292	$ 585,746	$ 510,643