Income Taxes - Income Tax Expense (Benefit) Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Tax at the statutory federal rate	$ 8,065	$ (323)	$ 182,700
State income taxes (net of federal benefit)	806	(32)	18,270
Decrease in valuation allowance	(941)	(164)	(86,882)
Fees and expenses for SEC investigation	0	1,092	0
Other	(783)	235	1,419
Total income tax expense	$ 7,147	$ 808	$ 115,507