Other Assets (Components Of Other Assets) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2013		Dec. 31, 2012
Other Assets [Line Items]
Income taxes receivable	$ 2,103		$ 1,970
Total	21,285		18,016
Real estate acquired through foreclosure	56		65
Reported Amount | Other assets
Other Assets [Line Items]
Collateral deposits, net	10,042		7,649
Unrealized gains on derivative financial instruments, net	4,511		4,556
Bank-owned life insurance	2,004		2,000
Investments in joint ventures and other unconsolidated entities	1,441		1,405
Receivable for securities settlement	536		33
Accounts receivable	634		511
Deferred tax assets, net of valuation allowance	336		353
Prepaid expenses	315		267
Deposits with clearing organizations	270		252
Income taxes receivable	174		174
Receivable for securities sold	497		1
Other	525	[1]	815	[1]
Total	$ 21,285		$ 18,016

[1] Included other real estate owned of approximately $56 million and $65 million, respectively.