Commitments, Contingencies and Guarantees (Commitments and Contingencies) (Details) $ in Millions	9 Months Ended
Aug. 31, 2020 USD ($)
Guarantor Obligations [Line Items]
2020	$ 10,178.6
2021	694.3
2022 and 2023	113.3
2024 and 2025	16.2
2026 and Later	12.2
Maximum Payout	$ 11,014.6
Guarantor obligation settled period	3 days
Equity commitments
Guarantor Obligations [Line Items]
2020	$ 59.3
2021	161.9
2022 and 2023	78.3
2024 and 2025	11.1
2026 and Later	12.2
Maximum Payout	322.8
Loan commitments
Guarantor Obligations [Line Items]
2020	0.0
2021	296.0
2022 and 2023	35.0
2024 and 2025	0.0
2026 and Later	0.0
Maximum Payout	331.0
Underwriting commitments
Guarantor Obligations [Line Items]
2020	64.0
2021	0.0
2022 and 2023	0.0
2024 and 2025	0.0
2026 and Later	0.0
Maximum Payout	64.0
Forward starting reverse repos
Guarantor Obligations [Line Items]
2020	6,184.5
2021	0.0
2022 and 2023	0.0
2024 and 2025	0.0
2026 and Later	0.0
Maximum Payout	6,184.5
Forward starting repos
Guarantor Obligations [Line Items]
2020	3,870.8
2021	100.0
2022 and 2023	0.0
2024 and 2025	0.0
2026 and Later	0.0
Maximum Payout	3,970.8
Other unfunded commitments
Guarantor Obligations [Line Items]
2020	0.0
2021	136.4
2022 and 2023	0.0
2024 and 2025	5.1
2026 and Later	0.0
Maximum Payout	141.5
Forward starting securities purchased under agreements to resell settled
Guarantor Obligations [Line Items]
Maximum Payout	6,183.8
Forward starting securities sold under agreements to repurchase settled
Guarantor Obligations [Line Items]
Maximum Payout	$ 3,670.6

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