Securitization Activities - Summary of Retained Interests in SPEs (Details) - USD ($) $ in Millions	Feb. 28, 2021	Nov. 30, 2020
Debt and Equity Securities, FV-NI [Line Items]
Total RMBS securitization assets	$ 505.5	$ 562.5
Total CMBS securitization assets	2,051.0	2,461.2
CLOs	5,712.5	3,345.5
Consumer and other loans	1,428.9	1,290.6
U.S. government agency RMBS
Debt and Equity Securities, FV-NI [Line Items]
Retained Interests	6.8	7.8
U.S. government agency CMBS
Debt and Equity Securities, FV-NI [Line Items]
Retained Interests	102.3	205.2
CLOs
Debt and Equity Securities, FV-NI [Line Items]
Retained Interests	70.2	39.5
Consumer and other loans
Debt and Equity Securities, FV-NI [Line Items]
Retained Interests	$ 77.8	$ 56.6