Variable Interest Entities (Details 2) (Variable Interest Entity Not Primary Beneficiary [Member], USD $) In Millions, unless otherwise specified	Nov. 30, 2011	Nov. 30, 2010
Total securities issued by securitization SPEs
Carrying Amount	$ 2,110.3	$ 2,796.1
Residential mortgage-backed securities [Member]
Total securities issued by securitization SPEs
Carrying Amount	1,324.5
Commercial mortgage-backed securities [Member]
Total securities issued by securitization SPEs
Carrying Amount	533.0
Collateralized Debt Obligations [Member]
Total securities issued by securitization SPEs
Carrying Amount	8.8
Other asset-backed securities [Member]
Total securities issued by securitization SPEs
Carrying Amount	14.0
Mortgage- and asset-backed securitization activity - Agency [Member]
Total securities issued by securitization SPEs
Carrying Amount	583.9
Mortgage-and asset- backed securitization activity - Non-agency [Member]
Total securities issued by securitization SPEs
Carrying Amount	1,410.9
Collateralized loan obligations [Member]
Total securities issued by securitization SPEs
Carrying Amount	48.2	35.3
Agency [Member]
Total securities issued by securitization SPEs
Carrying Amount	729.6
Agency [Member] | Mortgage- and asset-backed securitization activity - Agency [Member]
Total securities issued by securitization SPEs
Carrying Amount	539.9
Agency [Member] | Mortgage- and asset-backed securitization activity - Agency [Member] | Residential mortgage-backed securities [Member]
Total securities issued by securitization SPEs
Carrying Amount	67.9
Agency [Member] | Mortgage- and asset-backed securitization activity - Agency [Member] | Commercial mortgage-backed securities [Member]
Total securities issued by securitization SPEs
Carrying Amount	7.0
Agency [Member] | Mortgage- and asset-backed securitization activity - Agency [Member] | Collateralized Debt Obligations [Member]
Total securities issued by securitization SPEs
Carrying Amount	8.8
Agency [Member] | Mortgage- and asset-backed securitization activity - Agency [Member] | Other asset-backed securities [Member]
Total securities issued by securitization SPEs
Carrying Amount	13.8
Agency [Member] | Collateralized loan obligations [Member]
Total securities issued by securitization SPEs
Carrying Amount	48.2
Non Agency [Member]
Total securities issued by securitization SPEs
Carrying Amount	3,193.7
Non Agency [Member] | Mortgage-and asset- backed securitization activity - Non-agency [Member]
Total securities issued by securitization SPEs
Carrying Amount	1,410.9
Non Agency [Member] | Mortgage-and asset- backed securitization activity - Non-agency [Member] | Residential mortgage-backed securities [Member]
Total securities issued by securitization SPEs
Carrying Amount	1,256.7
Non Agency [Member] | Mortgage-and asset- backed securitization activity - Non-agency [Member] | Commercial mortgage-backed securities [Member]
Total securities issued by securitization SPEs
Carrying Amount	526.1
Non Agency [Member] | Mortgage-and asset- backed securitization activity - Non-agency [Member] | Collateralized Debt Obligations [Member]
Total securities issued by securitization SPEs
Carrying Amount	0
Non Agency [Member] | Mortgage-and asset- backed securitization activity - Non-agency [Member] | Other asset-backed securities [Member]
Total securities issued by securitization SPEs
Carrying Amount	0
Non Agency [Member] | Collateralized loan obligations [Member]
Total securities issued by securitization SPEs
Carrying Amount	$ 0