Derivative Instruments - Volumes and Weighted Average Price (Details) - Swap	12 Months Ended
	Dec. 31, 2017 MMBTU MBbls $ / shares
Natural Gas | January 2018 - March 2018
Oil and gas contracts
Daily Volumes | MMBTU	35,000
Weighted Average Price	$ 3.24
Crude Oil | January 2018 - December 2018
Oil and gas contracts
Daily Volumes | MBbls	0.250
Weighted Average Price	$ 55.00