v3.3.1.900
Disclosures About Oil and Gas Producing Activities - Commodity Prices Inclusive of Adjustments for Quality and Location Used in Determining Future Net Revenues Related to Standardized Measure Calculation (Detail) - Reserve Estimate [Member]
12 Months Ended
Dec. 31, 2015
$ / bbl
$ / Mcf
Dec. 31, 2014
$ / bbl
$ / Mcf
Dec. 31, 2013
$ / bbl
$ / Mcf
Oil (MBbls) [Member]      
Average Sales Price and Production Costs Per Unit of Production [Line Items]      
Commodity Prices 50.16 94.56 97.28
NGLs (MBbls) [Member]      
Average Sales Price and Production Costs Per Unit of Production [Line Items]      
Commodity Prices 15.13 31.50 30.16
Natural Gas (MMcf) [Member]      
Average Sales Price and Production Costs Per Unit of Production [Line Items]      
Commodity Prices | $ / Mcf 2.64 4.55 3.66