Securitization Activities - Summary of Retained Interests in SPEs (Detail) - USD ($) $ in Millions	Nov. 30, 2016	Nov. 30, 2015
Securitization Vehicles [Line Items]
Total RMBS securitization assets	$ 7,584.9	$ 10,901.9
Total CMBS securitization assets	1,806.3	2,313.4
Total Collateralized loan obligations	4,102.2	4,538.4
Consumer and other loans	395.7	655.0
U.S. government agency residential mortgage-backed securities [Member]
Securitization Vehicles [Line Items]
Retained Interests	31.0	203.6
U.S. government agency commercial mortgage-backed securities [Member]
Securitization Vehicles [Line Items]
Retained Interests	29.6	87.2
Collateralized loan obligations [Member]
Securitization Vehicles [Line Items]
Retained Interests	37.0	51.5
Other [Member]
Securitization Vehicles [Line Items]
Retained Interests	$ 25.3	$ 31.0