Risk Management and Derivative Instruments- Balance Sheet Presentation (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Total derivative financial instruments - current liabilities	$ (6,062)	$ (3,433)
Total derivative financial instruments - noncurrent liabilities	(950)	(562)
Commodity Derivatives | Not designated as Hedging Instrument
Total derivative financial instruments - current assets		762
Total derivative financial instruments - current liabilities	(6,062)	(3,433)
Total derivative financial instruments - noncurrent liabilities	(950)	(562)
Total derivative fair value at period end	(7,012)	(3,233)
Derivative assets:
Gross Recognized Assets	6,255	4,384
Gross Amounts Offset, Assets	(6,255)	(3,622)
Net Recognized Fair Value Assets		762
Derivative liabilities:
Gross Recognized Liabilities	(13,267)	(7,617)
Gross Amounts Offset, Liabilities	6,255	3,622
Net Recognized Fair Value Liabilities	(7,012)	(3,995)
Current Assets | Commodity Derivatives | Not designated as Hedging Instrument
Derivative assets:
Gross Recognized Assets	2,134	3,479
Gross Amounts Offset, Assets	(2,134)	(2,717)
Net Recognized Fair Value Assets		762
Current Assets | Commodity Derivatives | Not designated as Hedging Instrument | Leasehold interest swap | Natural gas
Total derivative financial instruments - current assets		821
Current Assets | Commodity Derivatives | Not designated as Hedging Instrument | Collars | Oil
Total derivative financial instruments - current assets		(760)
Current Assets | Commodity Derivatives | Not designated as Hedging Instrument | Collars | Natural gas
Total derivative financial instruments - current assets		701
Non-Current Assets | Commodity Derivatives | Not designated as Hedging Instrument
Derivative assets:
Gross Recognized Assets	4,121	905
Gross Amounts Offset, Assets	(4,121)	(905)
Current Liabilities | Commodity Derivatives | Not designated as Hedging Instrument
Derivative liabilities:
Gross Recognized Liabilities	(8,196)	(6,150)
Gross Amounts Offset, Liabilities	2,134	2,717
Net Recognized Fair Value Liabilities	(6,062)	(3,433)
Current Liabilities | Commodity Derivatives | Not designated as Hedging Instrument | Leasehold interest swap | Oil
Total derivative financial instruments - current liabilities	(4,291)	(3,679)
Current Liabilities | Commodity Derivatives | Not designated as Hedging Instrument | Leasehold interest swap | Natural gas
Total derivative financial instruments - current liabilities	(131)
Current Liabilities | Commodity Derivatives | Not designated as Hedging Instrument | Collars | Oil
Total derivative financial instruments - current liabilities	(2,494)	(370)
Current Liabilities | Commodity Derivatives | Not designated as Hedging Instrument | Collars | Natural gas
Total derivative financial instruments - current liabilities	854	616
Non-Current Liabilities | Commodity Derivatives | Not designated as Hedging Instrument
Derivative liabilities:
Gross Recognized Liabilities	(5,071)	(1,467)
Gross Amounts Offset, Liabilities	4,121	905
Net Recognized Fair Value Liabilities	(950)	(562)
Non-Current Liabilities | Commodity Derivatives | Not designated as Hedging Instrument | Collars | Oil
Total derivative financial instruments - noncurrent liabilities	$ (950)	(523)
Non-Current Liabilities | Commodity Derivatives | Not designated as Hedging Instrument | Collars | Natural gas
Total derivative financial instruments - noncurrent liabilities		$ (39)