Supplemental Oil and Gas Reserve Information (Details 3)	12 Months Ended
	Dec. 31, 2016 $ / bbl $ / Mcf	Dec. 31, 2015 $ / bbl $ / Mcf	Dec. 31, 2014 $ / bbl $ / Mcf
Oil
Average Sales Price and Production Costs Per Unit of Production [Line Items]
Average sales price	36.60	45.75	90.48
Natural Gas Liquids
Average Sales Price and Production Costs Per Unit of Production [Line Items]
Average sales price	13.60	15.84	31.54
Natural Gas
Average Sales Price and Production Costs Per Unit of Production [Line Items]
Average sales price | $ / Mcf	2.36	2.52	4.27