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 |