v2.4.0.6
Equity Method Investments (Investees) (Details) (USD $)
In Millions, unless otherwise specified
 12 Months Ended
Dec. 31, 2012
Dec. 31, 2011
Dec. 31, 2010
Schedule of Equity Method Investments [Line Items]      
Equity method investment $ 4,682 $ 4,524  
MUMSS
      
Schedule of Equity Method Investments [Line Items]      
Percent ownership 40.00%    
Equity method investment 1,428 [1] 1,444 [1]  
Equity Method Investment, Summarized Financial Information [Abstract]      
Total assets 141,635 158,363  
Total liabilities 138,742 155,555  
Noncontrolling interest 41 22  
Net revenues 2,365 735 1,073
Income (loss) from continuing operations before income taxes 333 (1,746) (253)
Net income (loss) 405 (1,976) (156)
Net income (loss) applicable to equity method investee 397 (1,976) (144)
Lansdowne Partners
      
Schedule of Equity Method Investments [Line Items]      
Percent ownership 19.80% [2]    
Equity method investment 221 [1],[2] 276 [1],[2]  
Avenue Capital Group
      
Schedule of Equity Method Investments [Line Items]      
Equity method investment $ 224 [1],[2],[3] $ 237 [1],[2],[3]  
Maximum
      
Schedule of Equity Method Investments [Line Items]      
Minimum limited partnership threshold 5.00%    
Minimum
      
Schedule of Equity Method Investments [Line Items]      
Minimum limited partnership threshold 3.00%    
[1] Book value of these investees exceeds the Company’s share of net assets, reflecting equity method intangible assets and equity method goodwill.
[2] The Company’s ownership interest represents limited partnership interests. The Company is deemed to have significant influence in these limited partnerships, as the Company’s limited partnership interests were above the 3% to 5% threshold for interests that should be accounted for under the equity method.
[3] The Company’s ownership interest represents limited partnership interests in a number of different entities within the Avenue Capital Group.