Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
Net income	$ 103,324	$ 41,880	$ 158,295	$ 116,699
Other comprehensive income, net of tax:
Change in value of derivatives	21	21	42	61
Other comprehensive income	21	21	42	61
Comprehensive income	$ 103,345	$ 41,901	$ 158,337	$ 116,760