v2.4.0.6
Derivatives - Commodity Derivative Volumes and Prices (Detail)
Mar. 31, 2013
bbl
Crude Oil Basis Differential March 2013 - December 2013 [Member] | Swap [Member]
 
Derivative [Line Items]  
Volume Transacted 2,300
Contract Price 1.10
Natural Gas - 2013 Contract One [Member] | Swap [Member]
 
Derivative [Line Items]  
Volume Transacted 200,000
Contract Price 3.54
Natural Gas - 2013 Contract Two [Member] | Swap [Member]
 
Derivative [Line Items]  
Volume Transacted 190,000
Contract Price 3.80
Natural Gas - 2014 [Member] | Swap [Member]
 
Derivative [Line Items]  
Volume Transacted 360,000
Contract Price 4.18
Crude Oil - 2013 Contract One [Member] | Collar [Member]
 
Derivative [Line Items]  
Volume Transacted 650
Crude Oil - 2013 Contract One [Member] | Minimum [Member] | Collar [Member]
 
Derivative [Line Items]  
Contract Price 90.00
Crude Oil - 2013 Contract One [Member] | Maximum [Member] | Collar [Member]
 
Derivative [Line Items]  
Contract Price 105.80
Crude Oil - 2013 Contract Two [Member] | Collar [Member]
 
Derivative [Line Items]  
Volume Transacted 450
Crude Oil - 2013 Contract Two [Member] | Minimum [Member] | Collar [Member]
 
Derivative [Line Items]  
Contract Price 90.00
Crude Oil - 2013 Contract Two [Member] | Maximum [Member] | Collar [Member]
 
Derivative [Line Items]  
Contract Price 101.45
Crude Oil February 2013 December 2013 [Member] | Collar [Member]
 
Derivative [Line Items]  
Volume Transacted 1,200
Crude Oil February 2013 December 2013 [Member] | Minimum [Member] | Collar [Member]
 
Derivative [Line Items]  
Contract Price 90.35
Crude Oil February 2013 December 2013 [Member] | Maximum [Member] | Collar [Member]
 
Derivative [Line Items]  
Contract Price 100.35
Crude Oil - 2014 [Member] | Collar [Member]
 
Derivative [Line Items]  
Volume Transacted 550
Crude Oil - 2014 [Member] | Minimum [Member] | Collar [Member]
 
Derivative [Line Items]  
Contract Price 90.00
Crude Oil - 2014 [Member] | Maximum [Member] | Collar [Member]
 
Derivative [Line Items]  
Contract Price 105.50