CONDENSED CONSOLIDATED STATEMENT OF COMPREHENSIVE INCOME (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 25,943	$ 40,758
Other comprehensive loss, net of tax effect:
Derivatives	(6,590)	(18,341)
Foreign currency translation	(499)
Comprehensive income	$ 18,854	$ 22,417