Provision (Benefit) for Income Taxes (Details 2) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Reconciliations of income taxes computed using the U.S. Federal statutory rate to the effective income tax rates
Income taxes (or benefits) computed at U.S. statutory rate	$ (607,080)	$ (151,714)	$ 69
State tax provisions (benefits), net of federal benefits	(18,064)	(5,935)	(184)
Non-deductible equity compensation	252	666	1,127
Stock-based compensation tax shortfall	1,703	2,409	558
Valuation allowances	542,289	4,635	385
Expired operating loss carryovers	333	288	400
Other, net	24	(392)	285
Income tax provision (benefit)	$ (80,543)	$ (150,043)	$ 2,640
Effective rate	4.60%	34.60%	1333.40%