Securitization Activities (Summary of Retained Interests in SPEs) (Details) - USD ($) $ in Millions	Aug. 31, 2020	Nov. 30, 2019
U.S. government agency residential mortgage-backed securities
Securitization or Asset-backed Financing Arrangement, Financial Asset for which Transfer is Accounted as Sale [Line Items]
U.S. government agency residential mortgage-backed securities	$ 928.7	$ 10,671.7
Retained Interests	12.4	103.3
U.S. government agency commercial mortgage-backed securities
Securitization or Asset-backed Financing Arrangement, Financial Asset for which Transfer is Accounted as Sale [Line Items]
U.S. government agency commercial mortgage-backed securities	439.2	1,374.8
Retained Interests	138.3	45.8
CLOs
Securitization or Asset-backed Financing Arrangement, Financial Asset for which Transfer is Accounted as Sale [Line Items]
CLOs	3,419.9	3,006.7
Retained Interests	41.8	58.4
Consumer and other loans
Securitization or Asset-backed Financing Arrangement, Financial Asset for which Transfer is Accounted as Sale [Line Items]
Consumer and other loans	884.0	1,149.3
Retained Interests	$ 45.6	$ 71.8