Fair Value Measurements - Schedule of Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Warrants and Rights Outstanding	$ (1,055)	$ (1,471)
Deferred Compensation Liability, Current and Noncurrent	(1,903)	(314)
Fair Value, Net Asset (Liability)	19,734	(23,451)
Commodity Derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	23,143	472
Liabilities	(451)	(22,138)
Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Warrants and Rights Outstanding	0	0
Deferred Compensation Liability, Current and Noncurrent	(1,267)	0
Fair Value, Net Asset (Liability)	(1,267)	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Commodity Derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	0	0
Liabilities	0	0
Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Warrants and Rights Outstanding	0	0
Deferred Compensation Liability, Current and Noncurrent	0	0
Fair Value, Net Asset (Liability)	22,692	(21,666)
Significant Other Observable Inputs (Level 2) | Commodity Derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	23,143	472
Liabilities	(451)	(22,138)
Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Warrants and Rights Outstanding	(1,055)	(1,471)
Deferred Compensation Liability, Current and Noncurrent	(636)	(314)
Fair Value, Net Asset (Liability)	(1,691)	(1,785)
Significant Unobservable Inputs (Level 3) | Commodity Derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	0	0
Liabilities	$ 0	$ 0