Net Interest Revenue (Components Of Interest Revenue And Interest Expenses) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2009
Net Interest Revenue [Abstract]
Deposits with banks	$ 149		$ 93		$ 156
U.S. Treasury and federal agencies	775		682		520
State and political subdivisions	221		222		225
Other investments	1,493		2,109		2,075
Securities purchased under resale agreements and federal funds sold	28		24		24
Loans and leases	278	[1]	329	[1]	239	[1]
Trading account assets					20
Interest revenue associated with AMLF					25	[2]
Other interest-earning assets	2		3		2
Total interest revenue	2,946		3,462		3,286
Deposits	220		213		195
Short-term borrowings	96	[1]	257	[1]	200	[1]
Long-term debt	289		286		304
Interest expense associated with AMLF					18	[2]
Other interest-bearing liabilities	8		7		5
Total interest expense	613		763		722
Net interest revenue	2,333		2,699		2,564
Interest expense included in short-term borrowings relating to third-party asset-backed securitization trusts			$ 67

[1] Amounts for 2010 included $67 million of interest revenue and interest expense related to the third-party asset-backed securitization trusts consolidated into our financial statements on January 1, 2010 in connection with our adoption of new GAAP. These trusts were de-consolidated in June 2010.

[2] Refers to the Federal Reserve's Asset-Backed Commercial Paper Money Market Mutual Fund Liquidity Facility, or AMLF, which expired in February 2010.