Commitments And Contingencies (Schedule Of Repurchase Agreements) (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Commitments and Contingencies Disclosure [Abstract]
Aggregate fair value of indemnified securities financing	$ 305,721	$ 302,342
Aggregate fair value of cash and securities held as collateral for indemnified securities financing	317,151	312,598
Aggregate fair value of collateral for indemnified securities financing invested in indemnified repurchase agreements	83,973	88,656
Aggregate fair value of cash and securities held as collateral for indemnified repurchase agreements	$ 88,897	$ 93,039