Commitments, Contingencies and Guarantees - Guarantees (Detail) $ in Millions	May 31, 2017 USD ($)
Derivative contracts - non-credit related [Member]
Guarantee Obligations [Line Items]
2017	$ 20,314.7
2018	2,621.4
2019 and 2020	35.2
2021 and 2022	0.0
2023 and Later	447.6
Notional/ Maximum Payout	23,418.9
Written derivative contracts - credit related [Member]
Guarantee Obligations [Line Items]
2017	0.0
2018	54.0
2019 and 2020	12.5
2021 and 2022	1,007.7
2023 and Later	0.0
Notional/ Maximum Payout	1,074.2
Derivatives [Member]
Guarantee Obligations [Line Items]
2017	20,314.7
2018	2,675.4
2019 and 2020	47.7
2021 and 2022	1,007.7
2023 and Later	447.6
Notional/ Maximum Payout	$ 24,493.1