Commitments and Contingencies - Additional Information (Details) gal in Thousands, a in Thousands		12 Months Ended
	Nov. 04, 2015 USD ($) a	Dec. 31, 2008 gal	Mar. 31, 2016 MMBoe
Crude Oil and Natural Gas
Long-term Purchase Commitment [Line Items]
Delivery commitments (MMBOE) | MMBoe			5.3
Sylacauga, Talladega County, Alabama
Long-term Purchase Commitment [Line Items]
Gallons of wastewater transported | gal		3
Pending Litigation | Energen vs. Endeavor Energy Resources
Long-term Purchase Commitment [Line Items]
Number of acres with cloud on the title | a	10
Damages sought | $	$ 300,000,000