Commitments, Contingencies and Guarantees - Guarantees (Details) $ in Millions	Aug. 31, 2020 USD ($)
Derivative contracts—non-credit related
Guarantee Obligations [Line Items]
2020	$ 6,295.6
2021	4,149.9
2022 and 2023	6,458.1
2024 and 2025	1,345.6
2026 and Later	52.0
Notional/ Maximum Payout	18,301.2
Written derivative contracts—credit related
Guarantee Obligations [Line Items]
2020	0.0
2021	0.0
2022 and 2023	1.0
2024 and 2025	5.4
2026 and Later	0.0
Notional/ Maximum Payout	6.4
Total derivative contracts
Guarantee Obligations [Line Items]
2020	6,295.6
2021	4,149.9
2022 and 2023	6,459.1
2024 and 2025	1,351.0
2026 and Later	52.0
Notional/ Maximum Payout	$ 18,307.6