Accrued Liabilities - Schedule of Accrued Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Jan. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Bonus payable	$ 2,060		$ 2,250
Payroll payable	27		18
Accrued interest - other	86		1,015
Accrued rent	210		156
Accrued well costs	13,353		8,386
Third party payments for joint interest expenditures	1,449		0
Accrued severance, property and franchise taxes	1,904		115
Accrued federal income tax	441		1,147
Other	569		728
Total accrued liabilities	27,130		16,583
8.750% Senior Notes Due April 15, 2019
Debt Instrument [Line Items]
Accrued interest - Senior Notes	$ 0		2,768
Debt instrument interest rate	8.75%	8.75%
11.25% Senior Notes
Debt Instrument [Line Items]
Accrued interest - Senior Notes	$ 7,031		$ 0
Debt instrument interest rate	11.25%	11.25%