Variable Interest Entities (Summary Of Securities Issued By Securitization SPEs) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2014		Dec. 31, 2013
Variable Interest Entity [Line Items]
Carrying Amount	$ 2,664.8		$ 2,122.3
Mortgage-And Asset-Backed Securitizations-Agency [Member]
Variable Interest Entity [Line Items]
Carrying Amount	1,733.2
Mortgage-And Asset-Backed Securitizations-Non-agency [Member]
Variable Interest Entity [Line Items]
Carrying Amount	862.4
Collateralized Loan Obligations [Member]
Variable Interest Entity [Line Items]
Carrying Amount	24.2	[1]	11.9	[1]
Mortgage-And Asset-Backed Securities [Member]
Variable Interest Entity [Line Items]
Carrying Amount	5,095.9
Residential Mortgage-Backed Securities [Member]
Variable Interest Entity [Line Items]
Carrying Amount	1,791.1
Commercial Mortgage-Backed Securities [Member]
Variable Interest Entity [Line Items]
Carrying Amount	644.1
Collateralized Debt Obligations [Member]
Variable Interest Entity [Line Items]
Carrying Amount	22.7
Other Asset-Backed Securities [Member]
Variable Interest Entity [Line Items]
Carrying Amount	18.2
Non-Agency [Member] | Mortgage-And Asset-Backed Securitizations-Non-agency [Member]
Variable Interest Entity [Line Items]
Carrying Amount	862.4
Non-Agency [Member] | Collateralized Loan Obligations [Member]
Variable Interest Entity [Line Items]
Carrying Amount	24.2
Non-Agency [Member] | Mortgage-And Asset-Backed Securities [Member]
Variable Interest Entity [Line Items]
Carrying Amount	999.4
Non-Agency [Member] | Residential Mortgage-Backed Securities [Member]
Variable Interest Entity [Line Items]
Carrying Amount	40.9
Non-Agency [Member] | Commercial Mortgage-Backed Securities [Member]
Variable Interest Entity [Line Items]
Carrying Amount	31.0
Non-Agency [Member] | Collateralized Debt Obligations [Member]
Variable Interest Entity [Line Items]
Carrying Amount	22.7
Non-Agency [Member] | Other Asset-Backed Securities [Member]
Variable Interest Entity [Line Items]
Carrying Amount	18.2
Agency [Member] | Mortgage-And Asset-Backed Securitizations-Agency [Member]
Variable Interest Entity [Line Items]
Carrying Amount	1,733.2
Agency [Member] | Mortgage-And Asset-Backed Securities [Member]
Variable Interest Entity [Line Items]
Carrying Amount	4,096.5
Agency [Member] | Residential Mortgage-Backed Securities [Member]
Variable Interest Entity [Line Items]
Carrying Amount	1,750.2
Agency [Member] | Commercial Mortgage-Backed Securities [Member]
Variable Interest Entity [Line Items]
Carrying Amount	$ 613.1

[1] Assets consist of debt securities and participation interests in corporate loans accounted for at fair value, which are included within Trading assets. Liabilities consist of forward sale agreements and a guarantee provided to a CLO managed by Jefferies Finance, which are accounted for at fair value and included within Trading liabilities.