Securitization Activities - Summary of Retained Interests in SPEs (Detail) - USD ($) $ in Millions	Nov. 30, 2015	Nov. 30, 2014
Securitization Vehicles [Line Items]
Total RMBS securitization assets	$ 10,901.9	$ 19,196.9
Total CMBS securitization assets	2,313.4	5,848.5
Total Collateralized loan obligations	4,538.4	4,511.8
Consumer and other loans	655.0
U.S. government agency residential mortgage-backed securities [Member]
Securitization Vehicles [Line Items]
Retained Interests	203.6	226.9
U.S. government agency commercial mortgage-backed securities [Member]
Securitization Vehicles [Line Items]
Retained Interests	87.2	204.7
Collateralized loan obligations [Member]
Securitization Vehicles [Line Items]
Retained Interests	51.5	$ 108.4
Other [Member]
Securitization Vehicles [Line Items]
Retained Interests	$ 31.0