Debt - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	Feb. 28, 2013	Nov. 30, 2012	Feb. 28, 2013 Unsecured Publicly-Traded Notes	Dec. 31, 2012 Unsecured Publicly-Traded Notes	Feb. 28, 2013 Unsecured Floating Rate Export Credit Facilities	Feb. 28, 2013 Unsecured Debt	Feb. 28, 2013 Unsecured Debt Commercial Paper	Feb. 28, 2013 Unsecured Debt Euro Denominated Bank Loans
Debt Instrument [Line Items]
Short-term borrowing	$ 122	$ 56					$ 76	$ 46
Aggregate weighted average interest rate						0.20%
Issuance of unsecured publicly-traded notes			$ 500	$ 500
Debt instrument, interest rate			1.20%	1.90%
Debt instrument maturity period			2016-02	2017-12
Debt instrument maturity year					2022