Securitization Activities - Summary of Retained Interests in SPEs (Detail) (USD $) In Millions, unless otherwise specified	May 31, 2014	Nov. 30, 2013
Securitization Vehicles [Line Items]
Total RMBS securitization assets	$ 11,466.7	$ 11,518.4
Total CMBS securitization assets	3,655.2	5,385.6
Total Collateralized loan obligations	728.5	728.5
U.S. government agency residential mortgage-backed securities [Member]
Securitization Vehicles [Line Items]
Fair Value of Securitizations Initially Retained	254.3	281.3
U.S. government agency commercial mortgage-backed securities [Member]
Securitization Vehicles [Line Items]
Fair Value of Securitizations Initially Retained	100.2	96.8
Collateralized loan obligations securitizations [Member]
Securitization Vehicles [Line Items]
Fair Value of Securitizations Initially Retained	$ 8.6	$ 9.0