Commitments, Guarantees, and Contingencies (Schedule Of Repurchase Agreements) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Commitments and Contingencies Disclosure [Abstract]
Aggregate fair value of indemnified securities financing	$ 314,940	$ 302,341
Aggregate fair value of cash and securities held by us, as agent, as collateral for indemnified securities financing	327,948	312,223
Aggregate fair value of collateral for indemnified securities financing invested in indemnified repurchase agreements	89,185	80,224
Aggregate fair value of cash and securities held by us or our agents as collateral for indemnified repurchase agreements	$ 94,549	$ 85,411