Condensed Consolidated Statements of Comprehensive Income (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Net income	$ 43,136	$ 14,263	$ 64,960	$ 22,786
Other comprehensive income, net of tax:
Unrealized gain on interest rate swaps	649	1,596	2,228	3,192
Comprehensive income	$ 43,785	$ 15,859	$ 67,188	$ 25,978