Fair Value Measurements (Details) (Recurring [Member], USD $)
In Thousands, unless otherwise specified
Feb. 28, 2014
Financial Assets:  
Commodity derivative asset   
Financial Liabilities:  
Derivative liability, Net 1,818
Level 1 [Member]
 
Financial Assets:  
Commodity derivative asset   
Financial Liabilities:  
Derivative liability, Net   
Level 2 [Member]
 
Financial Assets:  
Commodity derivative asset   
Financial Liabilities:  
Derivative liability, Net 1,818
Level 3 [Member]
 
Financial Assets:  
Commodity derivative asset   
Financial Liabilities:  
Derivative liability, Net