Consolidated Statements of Comprehensive Income (Loss) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Net income	$ 41,880	$ 36,417	$ 116,699	$ 118,179
Other Comprehensive Income, Net of Tax
Change in value of derivatives	21	148	61	196
Other comprehensive income	21	148	61	196
Comprehensive income	$ 41,901	$ 36,565	$ 116,760	$ 118,375