Income Taxes - Components of Tax Expense (Details) - USD ($) $ in Thousands	3 Months Ended					12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Dec. 31, 2016	Dec. 31, 2015
Current
Federal						$ 542	$ 253
State						364	183
Total current						906	436
Deferred
Federal						(93,383)
State						(17,044)
Total deferred						(110,427)
Total income tax expense	$ (438)	$ (38)	$ 110,065	$ (68)	$ (436)	$ (109,521)	$ 436