Outstanding Basis Swaps (Detail)
Dec. 31, 2013
MMBTU
2014 Swap Gas
 
Derivative Instruments And Hedging Activities [Line Items]  
Bbl per Day 1,000
Weighted Average Price Differential per MMBtu 0.590
2014 Swap Gas | Oil and gas commodity contracts
 
Derivative Instruments And Hedging Activities [Line Items]  
Bbl per Day 5,000
Weighted Average Swap Price Per Bbl 4.165
2014 Swap Oil | Oil and gas commodity contracts
 
Derivative Instruments And Hedging Activities [Line Items]  
Bbl per Day 5,500
Weighted Average Swap Price Per Bbl 92.94