Credit Quality And Allowance For Credit Losses (Loans By Credit Quality Indicator) (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2013		Dec. 31, 2012
Financing Receivable, Recorded Investment [Line Items]
Total loans	$ 45,459		$ 46,057
Special mention loans considered pass by regulatory authorities	180		303
Pass
Financing Receivable, Recorded Investment [Line Items]
Total loans	42,573	[1]	42,969	[1]
Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,399	[2]	1,482	[2]
Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,038	[3]	1,087	[3]
Nonaccrual
Financing Receivable, Recorded Investment [Line Items]
Total loans	449	[4]	519	[4]
Business loans
Financing Receivable, Recorded Investment [Line Items]
Total loans	41,724		42,377
Business loans | Pass
Financing Receivable, Recorded Investment [Line Items]
Total loans	38,994	[1]	39,461	[1]
Business loans | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,357	[2]	1,437	[2]
Business loans | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,017	[3]	1,065	[3]
Business loans | Nonaccrual
Financing Receivable, Recorded Investment [Line Items]
Total loans	356	[4]	414	[4]
Business loans | Commercial
Financing Receivable, Recorded Investment [Line Items]
Total loans	29,186		29,513
Business loans | Commercial | Pass
Financing Receivable, Recorded Investment [Line Items]
Total loans	27,505	[1]	28,032	[1]
Business loans | Commercial | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	950	[2]	820	[2]
Business loans | Commercial | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	629	[3]	558	[3]
Business loans | Commercial | Nonaccrual
Financing Receivable, Recorded Investment [Line Items]
Total loans	102	[4]	103	[4]
Business loans | Real estate construction
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,479		1,240
Business loans | Real estate construction | Pass
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,409	[1]	1,097	[1]
Business loans | Real estate construction | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	20	[2]	80	[2]
Business loans | Real estate construction | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	22	[3]	30	[3]
Business loans | Real estate construction | Nonaccrual
Financing Receivable, Recorded Investment [Line Items]
Total loans	28	[4]	33	[4]
Business loans | Real estate construction | Commercial Real Estate business line
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,223	[5]	1,049	[5]
Business loans | Real estate construction | Commercial Real Estate business line | Pass
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,164	[1],[5]	921	[1],[5]
Business loans | Real estate construction | Commercial Real Estate business line | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	18	[2],[5]	77	[2],[5]
Business loans | Real estate construction | Commercial Real Estate business line | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	15	[3],[5]	21	[3],[5]
Business loans | Real estate construction | Commercial Real Estate business line | Nonaccrual
Financing Receivable, Recorded Investment [Line Items]
Total loans	26	[4],[5]	30	[4],[5]
Business loans | Real estate construction | Other business lines
Financing Receivable, Recorded Investment [Line Items]
Total loans	256	[6]	191	[6]
Business loans | Real estate construction | Other business lines | Pass
Financing Receivable, Recorded Investment [Line Items]
Total loans	245	[1],[6]	176	[1],[6]
Business loans | Real estate construction | Other business lines | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	2	[2],[6]	3	[2],[6]
Business loans | Real estate construction | Other business lines | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	7	[3],[6]	9	[3],[6]
Business loans | Real estate construction | Other business lines | Nonaccrual
Financing Receivable, Recorded Investment [Line Items]
Total loans	2	[4],[6]	3	[4],[6]
Business loans | Commercial mortgage
Financing Receivable, Recorded Investment [Line Items]
Total loans	9,007		9,472
Business loans | Commercial mortgage | Pass
Financing Receivable, Recorded Investment [Line Items]
Total loans	8,061	[1]	8,262	[1]
Business loans | Commercial mortgage | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	356	[2]	471	[2]
Business loans | Commercial mortgage | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	364	[3]	464	[3]
Business loans | Commercial mortgage | Nonaccrual
Financing Receivable, Recorded Investment [Line Items]
Total loans	226	[4]	275	[4]
Business loans | Commercial mortgage | Commercial Real Estate business line
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,743	[5]	1,873	[5]
Business loans | Commercial mortgage | Commercial Real Estate business line | Pass
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,448	[1],[5]	1,479	[1],[5]
Business loans | Commercial mortgage | Commercial Real Estate business line | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	152	[2],[5]	213	[2],[5]
Business loans | Commercial mortgage | Commercial Real Estate business line | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	74	[3],[5]	87	[3],[5]
Business loans | Commercial mortgage | Commercial Real Estate business line | Nonaccrual
Financing Receivable, Recorded Investment [Line Items]
Total loans	69	[4],[5]	94	[4],[5]
Business loans | Commercial mortgage | Other business lines
Financing Receivable, Recorded Investment [Line Items]
Total loans	7,264	[6]	7,599	[6]
Business loans | Commercial mortgage | Other business lines | Pass
Financing Receivable, Recorded Investment [Line Items]
Total loans	6,613	[1],[6]	6,783	[1],[6]
Business loans | Commercial mortgage | Other business lines | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	204	[2],[6]	258	[2],[6]
Business loans | Commercial mortgage | Other business lines | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	290	[3],[6]	377	[3],[6]
Business loans | Commercial mortgage | Other business lines | Nonaccrual
Financing Receivable, Recorded Investment [Line Items]
Total loans	157	[4],[6]	181	[4],[6]
Business loans | Lease financing
Financing Receivable, Recorded Investment [Line Items]
Total loans	843		859
Business loans | Lease financing | Pass
Financing Receivable, Recorded Investment [Line Items]
Total loans	837	[1]	840	[1]
Business loans | Lease financing | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	4	[2]	9	[2]
Business loans | Lease financing | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	2	[3]	7	[3]
Business loans | Lease financing | Nonaccrual
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	[4]	3	[4]
Business loans | International
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,209		1,293
Business loans | International | Pass
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,182	[1]	1,230	[1]
Business loans | International | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	27	[2]	57	[2]
Business loans | International | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	[3]	6	[3]
Business loans | International | Nonaccrual
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	[4]	0	[4]
Retail loans
Financing Receivable, Recorded Investment [Line Items]
Total loans	3,735		3,680
Retail loans | Pass
Financing Receivable, Recorded Investment [Line Items]
Total loans	3,579	[1]	3,508	[1]
Retail loans | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	42	[2]	45	[2]
Retail loans | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	21	[3]	22	[3]
Retail loans | Nonaccrual
Financing Receivable, Recorded Investment [Line Items]
Total loans	93	[4]	105	[4]
Retail loans | Residential mortgage
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,611		1,527
Retail loans | Residential mortgage | Pass
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,532	[1]	1,438	[1]
Retail loans | Residential mortgage | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	10	[2]	12	[2]
Retail loans | Residential mortgage | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	7	[3]	7	[3]
Retail loans | Residential mortgage | Nonaccrual
Financing Receivable, Recorded Investment [Line Items]
Total loans	62	[4]	70	[4]
Retail loans | Consumer
Financing Receivable, Recorded Investment [Line Items]
Total loans	2,124		2,153
Retail loans | Consumer | Pass
Financing Receivable, Recorded Investment [Line Items]
Total loans	2,047	[1]	2,070	[1]
Retail loans | Consumer | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	32	[2]	33	[2]
Retail loans | Consumer | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	14	[3]	15	[3]
Retail loans | Consumer | Nonaccrual
Financing Receivable, Recorded Investment [Line Items]
Total loans	31	[4]	35	[4]
Retail loans | Consumer | Home equity
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,474		1,537
Retail loans | Consumer | Home equity | Pass
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,428	[1]	1,489	[1]
Retail loans | Consumer | Home equity | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	13	[2]	11	[2]
Retail loans | Consumer | Home equity | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	5	[3]	6	[3]
Retail loans | Consumer | Home equity | Nonaccrual
Financing Receivable, Recorded Investment [Line Items]
Total loans	28	[4]	31	[4]
Retail loans | Consumer | Other consumer
Financing Receivable, Recorded Investment [Line Items]
Total loans	650		616
Retail loans | Consumer | Other consumer | Pass
Financing Receivable, Recorded Investment [Line Items]
Total loans	619	[1]	581	[1]
Retail loans | Consumer | Other consumer | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	19	[2]	22	[2]
Retail loans | Consumer | Other consumer | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	9	[3]	9	[3]
Retail loans | Consumer | Other consumer | Nonaccrual
Financing Receivable, Recorded Investment [Line Items]
Total loans	$ 3	[4]	$ 4	[4]

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

[2] 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 $180 million and $303 million at June 30, 2013 and December 31, 2012, respectively, of loans proactively monitored by management that were considered “pass” by regulatory authorities.

[3] 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.

[4] 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 2012 Annual Report. 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.

[5] Primarily loans to real estate developers.

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