Income Taxes - Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Reconciliation of the expected income tax expense on income (loss) before income taxes using the statutory federal income tax rate
Income (loss) before income taxes	$ (26,900)	$ (5,000)	$ (6,700)
Statutory rate (as a percent)	35.00%
Effective federal income tax rate (as a percent)	35.00%	0.00%
Income tax expense (benefit) computed at statutory rate	$ (9,400)
Reconciling items
State income taxes (benefit), net of federal tax benefit	200
Nontaxable income allocated to non-controlling interest	1,900
Nontaxable income allocated to predecessor	5,300
Change in rates	1,400
Valuation allowance	1,000
Income Tax expense (benefit)	$ 400