Quarterly report pursuant to Section 13 or 15(d)

Derivative Instruments (Details Textual)

v2.4.0.8
Derivative Instruments (Details Textual) (USD $)
 3 Months Ended
May 31, 2014
May 31, 2013
Derivative [Line Items]    
Net gain (loss) on commodity swap contracts reported outside of segment operating results $ (5,500,000) $ (3,000,000)
Amount of net gains, net of income tax effect, to be reclassified from AOCI to earnings within the next 12 months 2,400,000  
Fair value of derivative instruments in a net liability position due to counterparties 28,000,000  
Fair value of derivative instruments in a net receivable position due from counterparties 19,100,000  
Commodity swap contracts [Member] | Unusual Items [Member]
    
Derivative [Line Items]    
Net gain (loss) on commodity swap contracts reported outside of segment operating results   $ 0
Not designated as hedging instrument [Member] | Foreign currency contracts [Member]
    
Derivative [Line Items]    
Maturity period for derivative instruments 12 months  
Not designated as hedging instrument [Member] | Commodity swap contracts [Member]
    
Derivative [Line Items]    
Maturity period for derivative instruments 36 months  
Designated as hedging instrument [Member] | Cash flow hedging [Member]
    
Derivative [Line Items]    
Average maturity period for cash flow hedges 3 years  
Maximum maturity period for cash flow hedges 5 years