Derivative Financial Instruments - Remaining Contract Maturity of Fair Value of OTC Derivative Assets and Liabilities (Footnote) (Detail) $ in Millions	May 31, 2016 USD ($)
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Exchange traded derivative assets	$ 53.2
Cash collateral received	139.5
Exchange traded derivative liabilities, with fair value	270.4
Cash collateral pledged	$ 226.8