Securities Financing Activities (Details) (USD $)	Dec. 31, 2012	Dec. 31, 2011
Components of collateralized financings [Abstract]
Securities purchased under resale agreements	$ 295,413,000,000	$ 235,000,000,000
Securities borrowed, at fair value	119,017,000,000	142,462,000,000
Securities sold under repurchase agreements	215,560,000,000	197,789,000,000
Securities loaned	23,582,000,000	14,214,000,000
Securities financing activities (Numeric) [Abstract]
Federal funds sold and securities purchased under resale agreements, at fair value	296,296,000,000	235,314,000,000
Resale and repurchase agreements that have been netted	96,900,000,000	115,700,000,000
Fair value
Components of collateralized financings [Abstract]
Securities borrowed, at fair value	10,200,000,000	15,300,000,000
Securities sold under repurchase agreements	3,900,000,000	6,800,000,000
Securities loaned	457,000,000
Securities financing activities (Numeric) [Abstract]
Federal funds sold and securities purchased under resale agreements, at fair value	$ 24,300,000,000	$ 22,200,000,000