Commitments, Contingencies and Guarantees - Commitments and Contingencies (Detail) $ in Millions	3 Months Ended
	Feb. 28, 2017 USD ($)
Other Commitments [Line Items]
2017	$ 6,385.3
2018	146.0
2019 and 2020	297.7
2021 and 2022	92.4
2023 and Later	245.7
Notional/ Maximum Payout	$ 7,167.1
Guarantor obligation settled period (in days)	3 days
Equity commitments [Member]
Other Commitments [Line Items]
2017	$ 0.0
2018	9.4
2019 and 2020	11.1
2021 and 2022	0.0
2023 and Later	233.0
Notional/ Maximum Payout	253.5
Loan commitments [Member]
Other Commitments [Line Items]
2017	294.4
2018	11.9
2019 and 2020	65.0
2021 and 2022	56.2
2023 and Later	0.0
Notional/ Maximum Payout	427.5
Mortgage-related and other purchase commitments [Member]
Other Commitments [Line Items]
2017	0.0
2018	0.0
2019 and 2020	217.0
2021 and 2022	0.0
2023 and Later	0.0
Notional/ Maximum Payout	217.0
Underwriting commitments [Member]
Other Commitments [Line Items]
2017	0.1
2018	0.0
2019 and 2020	0.0
2021 and 2022	0.0
2023 and Later	0.0
Notional/ Maximum Payout	0.1
Forward starting reverse repos [Member]
Other Commitments [Line Items]
2017	3,346.5
2018	0.0
2019 and 2020	0.0
2021 and 2022	0.0
2023 and Later	0.0
Notional/ Maximum Payout	3,346.5
Guarantor obligation settled amount	3,303.6
Forward starting repos [Member]
Other Commitments [Line Items]
2017	2,609.3
2018	0.0
2019 and 2020	0.0
2021 and 2022	0.0
2023 and Later	0.0
Notional/ Maximum Payout	2,609.3
Guarantor obligation settled amount	2,609.3
Other unfunded commitments [Member]
Other Commitments [Line Items]
2017	135.0
2018	124.7
2019 and 2020	4.6
2021 and 2022	36.2
2023 and Later	12.7
Notional/ Maximum Payout	$ 313.2