Derivative Financial Instruments - Counterparty Credit Quality with Respect to Fair Value of OTC Derivatives Assets (Detail) $ in Thousands |
May 31, 2016
USD ($)
|
|---|---|
| Derivative Instruments and Hedging Activities Disclosure [Abstract] | |
| Fair value of OTC derivatives assets, Counterparty credit quality, A- or higher | $ 179,929 |
| Fair value of OTC derivatives assets, Counterparty credit quality, BBB- to BBB+ | 54,940 |
| Fair value of OTC derivatives assets, Counterparty credit quality, BB+ or lower | 101,674 |
| Fair value of OTC derivatives assets, Counterparty credit quality, Unrated | 61,239 |
| Total OTC derivative assets included in Financial instruments owned | $ 397,782 |