Derivative Financial Instruments - Remaining Contract Maturity of Fair Value of OTC Derivative Assets and Liabilities (Footnote) (Detail) $ in Millions	Feb. 28, 2017 USD ($)
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Exchange traded derivative assets	$ 15.5
Cash collateral received	176.5
Exchange traded derivative liabilities, with fair value	254.9
Cash collateral pledged	$ 144.2