Credit Quality And Allowance For Credit Losses (Loans By Credit Quality Indicator) (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2012		Dec. 31, 2011		Jun. 30, 2011
Total loans	$ 43,992		$ 42,679		$ 39,193
Business loans
Total loans	40,305		38,868		35,470
Business loans | Commercial
Total loans	27,016		24,996
Business loans | Real estate construction
Total loans	1,377		1,533
Business loans | Real estate construction | Commercial real estate business line
Total loans	991	[1]	1,103	[1]
Business loans | Real estate construction | Other business lines
Total loans	386	[2]	430	[2]
Business loans | Commercial mortgage
Total loans	9,830		10,264
Business loans | Commercial mortgage | Commercial real estate business line
Total loans	2,315	[1]	2,507	[1]
Business loans | Commercial mortgage | Other business lines
Total loans	7,515	[2]	7,757	[2]
Business loans | Lease Financing
Total loans	858		905
Business loans | International
Total loans	1,224		1,170
Retail Loans
Total loans	3,687		3,811		3,723
Retail Loans | Residential mortgage
Total loans	1,469		1,526
Retail Loans | Total consumer
Total loans	2,218		2,285
Retail Loans | Total consumer | Home equity
Total loans	1,584		1,655
Retail Loans | Total consumer | Other consumer
Total loans	634		630
Pass
Total loans	40,157	[3]	38,212	[3]
Pass | Business loans
Total loans	36,634	[3]	34,575	[3]
Pass | Business loans | Commercial
Total loans	25,332	[3]	23,206	[3]
Pass | Business loans | Real estate construction
Total loans	1,131	[3]	1,138	[3]
Pass | Business loans | Real estate construction | Commercial real estate business line
Total loans	777	[1],[3]	768	[1],[3]
Pass | Business loans | Real estate construction | Other business lines
Total loans	354	[2],[3]	370	[2],[3]
Pass | Business loans | Commercial mortgage
Total loans	8,182	[3]	8,269	[3]
Pass | Business loans | Commercial mortgage | Commercial real estate business line
Total loans	1,658	[1],[3]	1,728	[1],[3]
Pass | Business loans | Commercial mortgage | Other business lines
Total loans	6,524	[2],[3]	6,541	[2],[3]
Pass | Business loans | Lease Financing
Total loans	834	[3]	865	[3]
Pass | Business loans | International
Total loans	1,155	[3]	1,097	[3]
Pass | Retail Loans
Total loans	3,523	[3]	3,637	[3]
Pass | Retail Loans | Residential mortgage
Total loans	1,378	[3]	1,434	[3]
Pass | Retail Loans | Total consumer
Total loans	2,145	[3]	2,203	[3]
Pass | Retail Loans | Total consumer | Home equity
Total loans	1,546	[3]	1,600	[3]
Pass | Retail Loans | Total consumer | Other consumer
Total loans	599	[3]	603	[3]
Special Mention
Total loans	1,751	[4]	1,981	[4]
Special mention loans considered pass by regulatory authorities	366		481
Special Mention | Business loans
Total loans	1,705	[4]	1,935	[4]
Special Mention | Business loans | Commercial
Total loans	905	[4]	898	[4]
Special Mention | Business loans | Real estate construction
Total loans	126	[4]	162	[4]
Special Mention | Business loans | Real estate construction | Commercial real estate business line
Total loans	121	[1],[4]	139	[1],[4]
Special Mention | Business loans | Real estate construction | Other business lines
Total loans	5	[2],[4]	23	[2],[4]
Special Mention | Business loans | Commercial mortgage
Total loans	642	[4]	824	[4]
Special Mention | Business loans | Commercial mortgage | Commercial real estate business line
Total loans	324	[1],[4]	409	[1],[4]
Special Mention | Business loans | Commercial mortgage | Other business lines
Total loans	318	[2],[4]	415	[2],[4]
Special Mention | Business loans | Lease Financing
Total loans	13	[4]	18	[4]
Special Mention | Business loans | International
Total loans	19	[4]	33	[4]
Special Mention | Retail Loans
Total loans	46	[4]	46	[4]
Special Mention | Retail Loans | Residential mortgage
Total loans	7	[4]	12	[4]
Special Mention | Retail Loans | Total consumer
Total loans	39	[4]	34	[4]
Special Mention | Retail Loans | Total consumer | Home equity
Total loans	16	[4]	22	[4]
Special Mention | Retail Loans | Total consumer | Other consumer
Total loans	23	[4]	12	[4]
Substandard
Total loans	1,365	[5]	1,626	[5]
Substandard | Business loans
Total loans	1,343	[5]	1,580	[5]
Substandard | Business loans | Commercial
Total loans	604	[5]	655	[5]
Substandard | Business loans | Real estate construction
Total loans	51	[5]	132	[5]
Substandard | Business loans | Real estate construction | Commercial real estate business line
Total loans	33	[1],[5]	103	[1],[5]
Substandard | Business loans | Real estate construction | Other business lines
Total loans	18	[2],[5]	29	[2],[5]
Substandard | Business loans | Commercial mortgage
Total loans	631	[5]	744	[5]
Substandard | Business loans | Commercial mortgage | Commercial real estate business line
Total loans	178	[1],[5]	211	[1],[5]
Substandard | Business loans | Commercial mortgage | Other business lines
Total loans	453	[2],[5]	533	[2],[5]
Substandard | Business loans | Lease Financing
Total loans	7	[5]	17	[5]
Substandard | Business loans | International
Total loans	50	[5]	32	[5]
Substandard | Retail Loans
Total loans	22	[5]	46	[5]
Substandard | Retail Loans | Residential mortgage
Total loans	8	[5]	9	[5]
Substandard | Retail Loans | Total consumer
Total loans	14	[5]	37	[5]
Substandard | Retail Loans | Total consumer | Home equity
Total loans	6	[5]	28	[5]
Substandard | Retail Loans | Total consumer | Other consumer
Total loans	8	[5]	9	[5]
Nonaccrual
Total loans	719	[6]	860	[6]
Nonaccrual | Business loans
Total loans	623	[6]	778	[6]
Nonaccrual | Business loans | Commercial
Total loans	175	[6]	237	[6]
Nonaccrual | Business loans | Real estate construction
Total loans	69	[6]	101	[6]
Nonaccrual | Business loans | Real estate construction | Commercial real estate business line
Total loans	60	[1],[6]	93	[1],[6]
Nonaccrual | Business loans | Real estate construction | Other business lines
Total loans	9	[2],[6]	8	[2],[6]
Nonaccrual | Business loans | Commercial mortgage
Total loans	375	[6]	427	[6]
Nonaccrual | Business loans | Commercial mortgage | Commercial real estate business line
Total loans	155	[1],[6]	159	[1],[6]
Nonaccrual | Business loans | Commercial mortgage | Other business lines
Total loans	220	[2],[6]	268	[2],[6]
Nonaccrual | Business loans | Lease Financing
Total loans	4	[6]	5	[6]
Nonaccrual | Business loans | International
Total loans	0	[6]	8	[6]
Nonaccrual | Retail Loans
Total loans	96	[6]	82	[6]
Nonaccrual | Retail Loans | Residential mortgage
Total loans	76	[6]	71	[6]
Nonaccrual | Retail Loans | Total consumer
Total loans	20	[6]	11	[6]
Nonaccrual | Retail Loans | Total consumer | Home equity
Total loans	16	[6]	5	[6]
Nonaccrual | Retail Loans | Total consumer | Other consumer
Total loans	$ 4	[6]	$ 6	[6]

[1] Primarily loans to real estate investors and developers.

[2] Primarily loans secured by owner-occupied real estate.

[3] Includes all loans not included in the categories of special mention, substandard or nonaccrual.

[4] Special mention loans are accruing loans that have potential credit weaknesses that deserve management’s close attention, such as loans to borrowers who may be experiencing financial difficulties that may result in deterioration of repayment prospects from the borrower at some future date. Included in the special mention category were $366 million and $481 million at June 30, 2012 and December 31, 2011, respectively, of loans proactively monitored by management that were considered “pass” by regulatory authorities.

[5] Substandard loans are accruing loans that have a well-defined weakness, or weaknesses, such as loans to borrowers who may be experiencing losses from operations or inadequate liquidity of a degree and duration that jeopardizes the orderly repayment of the loan. Substandard loans also are distinguished by the distinct possibility of loss in the future if these weaknesses are not corrected. PCI loans are included in the substandard category. This category is generally consistent with the "substandard" category as defined by regulatory authorities.

[6] Nonaccrual loans are loans for which the accrual of interest has been discontinued. For further information regarding nonaccrual loans, refer to the Nonperforming Assets subheading in Note 1 - Summary of Significant Accounting Policies - on page F-59 in the Corporation's 2011 Annual Report and to Note 1 of these interim consolidated financial statements. A significant majority of nonaccrual loans are generally consistent with the "substandard" category and the remainder are generally consistent with the "doubtful" category as defined by regulatory authorities.