Supplementary Financial Information on Oil and Natural Gas Exploration, Development and Production Activities (Unaudited) - Narrative (Details)	12 Months Ended
	Dec. 31, 2015 $ / Mcf $ / bbl
Extractive Industries [Abstract]
Ownership percentage by noncontrolling owners	50.00%
Natural Gas
Average Sales Price and Production Costs Per Unit of Production [Line Items]
Benchmark sales price | $ / Mcf	2.58
Crude Oil
Average Sales Price and Production Costs Per Unit of Production [Line Items]
Benchmark sales price | $ / bbl	50.28
Minimum | Natural Gas
Average Sales Price and Production Costs Per Unit of Production [Line Items]
Average prices | $ / Mcf	2.85
Minimum | Crude Oil
Average Sales Price and Production Costs Per Unit of Production [Line Items]
Average prices | $ / bbl	39.41
Maximum | Natural Gas
Average Sales Price and Production Costs Per Unit of Production [Line Items]
Average prices | $ / Mcf	3.33
Maximum | Crude Oil
Average Sales Price and Production Costs Per Unit of Production [Line Items]
Average prices | $ / bbl	46.54