Commitments, Contingencies and Guarantees - Commitments and Contingencies (Details) $ in Millions	Nov. 30, 2019 USD ($)
Commitments And Guarantee Obligations [Line Items]
2020	$ 8,095.7
2021	178.6
2022 and 2023	10.0
2024 and 2025	14.2
2026 and Later	8.4
Maximum Payout	8,306.9
Equity commitments
Commitments And Guarantee Obligations [Line Items]
2020	115.8
2021	1.4
2022 and 2023	0.0
2024 and 2025	0.0
2026 and Later	8.4
Maximum Payout	125.6
Loan commitments
Commitments And Guarantee Obligations [Line Items]
2020	250.0
2021	45.0
2022 and 2023	10.0
2024 and 2025	9.3
2026 and Later	0.0
Maximum Payout	314.3
Underwriting commitments
Commitments And Guarantee Obligations [Line Items]
2020	13.5
2021	0.0
2022 and 2023	0.0
2024 and 2025	0.0
2026 and Later	0.0
Maximum Payout	13.5
Forward starting reverse repos
Commitments And Guarantee Obligations [Line Items]
2020	5,475.3
2021	0.0
2022 and 2023	0.0
2024 and 2025	0.0
2026 and Later	0.0
Maximum Payout	5,475.3
Forward starting repos
Commitments And Guarantee Obligations [Line Items]
2020	2,168.8
2021	0.0
2022 and 2023	0.0
2024 and 2025	0.0
2026 and Later	0.0
Maximum Payout	2,168.8
Other unfunded commitments
Commitments And Guarantee Obligations [Line Items]
2020	72.3
2021	132.2
2022 and 2023	0.0
2024 and 2025	4.9
2026 and Later	0.0
Maximum Payout	209.4
Forward Starting Securities Sold Under Agreements to Repurchase Settled Within Three Business Days
Commitments And Guarantee Obligations [Line Items]
Maximum Payout	$ 2,157.7