v2.4.0.6
Short Term Borrowings and Credit Lines - Additional Information (Detail) (USD $)
 1 Months Ended 12 Months Ended
Nov. 01, 2011
May 31, 2012
May 31, 2011
Debt Instrument [Line Items]      
Amounts outstanding under commercial paper program   $ 0 $ 0
External Credit Rating, Standard & Poor's
      
Debt Instrument [Line Items]      
Long-term senior unsecured debt rating   A+  
External Credit Rating, Moody's
      
Debt Instrument [Line Items]      
Long-term senior unsecured debt rating   A1  
New Credit Facilities
      
Debt Instrument [Line Items]      
Revolving credit facility, borrowing capacity 1,000,000,000    
Revolving credit facility, optional maximum borrowing capacity 1,500,000,000    
Revolving credit facility, optional extension period 1 year    
Revolving credit facility, interest rate margin above LIBOR rate   0.56%  
Revolving credit facility, fee   0.065%  
Revolving credit facility, amount outstanding   0 0
New Credit Facilities | Before Extension
      
Debt Instrument [Line Items]      
Revolving credit facility, maturity period November 2016    
New Credit Facilities | After Extension | Maximum
      
Debt Instrument [Line Items]      
Revolving credit facility, maturity period 2018-11-01    
Old Credit Facilities
      
Debt Instrument [Line Items]      
Revolving credit facility, borrowing capacity $ 1,000,000,000    
Revolving credit facility, maturity period December 2012    
Sojitz America Accounts Payable
      
Debt Instrument [Line Items]      
Accounts payable, due date period   60 days  
Accounts payable, interest rate margin above LIBOR   0.75%