Income Taxes - Provision for income taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Current:
Federal	$ 7,861	$ 99,377	$ 35,754
State	2,761	10,343	5,513
Foreign	11,569	11,534	10,358
Total current	22,191	121,254	51,625
Deferred:
Federal	(66,573)	(67,415)	(25,469)
State	(4,270)	(5,992)	(2,579)
Foreign	(1,317)	(1,322)	(1,118)
Total deferred	(72,160)	(74,729)	(29,166)
Total provision (benefit)	$ (49,969)	$ 46,525	$ 22,459