Income Taxes - Income Tax Expense (Benefit) Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Tax at the statutory federal rate	$ (323)	$ 182,700	$ 1,603
State income taxes (net of federal benefit)	(32)	18,270	160
Decrease in valuation allowance	(164)	(86,882)	(2,218)
Fees and expenses for SEC investigation	1,092	0	0
Other	235	1,419	46
Total income tax expense (benefit)	$ 808	$ 115,507	$ (409)