Annual report pursuant to Section 13 and 15(d)

Oil and Natural Gas Properties (Details)

v2.4.0.6
Oil and Natural Gas Properties (Details) (USD $)
In Thousands, unless otherwise specified
 12 Months Ended 2 Months Ended
Dec. 31, 2012
Dec. 31, 2011
Dec. 31, 2010
Dec. 31, 2012
Minimum [Member]
Dec. 31, 2012
Maximum [Member]
Mar. 07, 2013
Subsequent Event [Member]
horizontal_well
Vertical_Well
Oil and Gas Properties [Line Items]            
Capitalized Costs of Unproved Properties Excluded from Amortization, Cumulative $ 66,173 $ 841 $ 1,762      
Unevaluated Property Costs Expected Evaluation Period Range       3 years 5 years  
Capitalized Costs of Unproved Properties Excluded from Amortization, Period Cost $ 66,173          
Horizontal Exploration Wells Completed (in horizontal wells)           2
Vertical Exploration Wells Completed (in vertical wells)           2
Horizontal Exploration Wells Drilled (in horizontal wells)           3
Horizontal Exploration Wells, Drilling in Progress (in horizontal wells)           1
Average Production Costs Per Barrel of Oil Equivalents (BOE) 16.86 11.04 10.58      
Depletion Expense Per Physical Unit of Production (Boe) 31.56 26.42 19.00