Credit Quality And Allowance For Credit Losses (Loans By Credit Quality Indicator) (Details) - USD ($) $ in Millions		Dec. 31, 2015	Dec. 31, 2014
Financing Receivable, Recorded Investment [Line Items]
Total loans		$ 49,084	$ 48,593
Pass
Financing Receivable, Recorded Investment [Line Items]
Total loans	[1]	45,891	46,700
Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	[2]	1,579	831
Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	[3]	1,247	789
Nonaccrual
Financing Receivable, Recorded Investment [Line Items]
Total loans	[4]	367	273
Real estate construction
Financing Receivable, Recorded Investment [Line Items]
Total loans		2,001	1,955
Real estate construction | Commercial Real Estate business line
Financing Receivable, Recorded Investment [Line Items]
Total loans	[5]	1,681	1,606
Real estate construction | Other business lines
Financing Receivable, Recorded Investment [Line Items]
Total loans	[6]	320	349
Real estate
Financing Receivable, Recorded Investment [Line Items]
Total loans		8,977	8,604
Real estate | Commercial Real Estate business line
Financing Receivable, Recorded Investment [Line Items]
Total loans	[5]	2,104	1,790
Real estate | Other business lines
Financing Receivable, Recorded Investment [Line Items]
Total loans	[6]	6,873	6,814
Business loans | Commercial borrower
Financing Receivable, Recorded Investment [Line Items]
Total loans		44,729	44,380
Business loans | Commercial borrower | Pass
Financing Receivable, Recorded Investment [Line Items]
Total loans	[1]	41,621	42,572
Business loans | Commercial borrower | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	[2]	1,573	826
Business loans | Commercial borrower | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	[3]	1,222	776
Business loans | Commercial borrower | Nonaccrual
Financing Receivable, Recorded Investment [Line Items]
Total loans	[4]	313	206
Business loans | Commercial borrower | Domestic loans
Financing Receivable, Recorded Investment [Line Items]
Total loans		31,659	31,520
Business loans | Commercial borrower | Domestic loans | Pass
Financing Receivable, Recorded Investment [Line Items]
Total loans	[1]	29,117	30,310
Business loans | Commercial borrower | Domestic loans | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	[2]	1,293	560
Business loans | Commercial borrower | Domestic loans | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	[3]	1,011	541
Business loans | Commercial borrower | Domestic loans | Nonaccrual
Financing Receivable, Recorded Investment [Line Items]
Total loans	[4]	238	109
Business loans | Commercial borrower | International loans
Financing Receivable, Recorded Investment [Line Items]
Total loans		1,368	1,496
Business loans | Commercial borrower | International loans | Pass
Financing Receivable, Recorded Investment [Line Items]
Total loans	[1]	1,245	1,468
Business loans | Commercial borrower | International loans | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	[2]	59	15
Business loans | Commercial borrower | International loans | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	[3]	56	13
Business loans | Commercial borrower | International loans | Nonaccrual
Financing Receivable, Recorded Investment [Line Items]
Total loans	[4]	8	0
Business loans | Real estate construction | Commercial borrower | Domestic loans
Financing Receivable, Recorded Investment [Line Items]
Total loans		2,001	1,955
Business loans | Real estate construction | Commercial borrower | Domestic loans | Pass
Financing Receivable, Recorded Investment [Line Items]
Total loans	[1]	1,999	1,930
Business loans | Real estate construction | Commercial borrower | Domestic loans | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	[2]	1	18
Business loans | Real estate construction | Commercial borrower | Domestic loans | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	[3]	0	5
Business loans | Real estate construction | Commercial borrower | Domestic loans | Nonaccrual
Financing Receivable, Recorded Investment [Line Items]
Total loans	[4]	1	2
Business loans | Real estate construction | Commercial borrower | Domestic loans | Commercial Real Estate business line
Financing Receivable, Recorded Investment [Line Items]
Total loans	[7],[8]	1,681	1,606
Business loans | Real estate construction | Commercial borrower | Domestic loans | Commercial Real Estate business line | Pass
Financing Receivable, Recorded Investment [Line Items]
Total loans	[1],[7]	1,681	1,594
Business loans | Real estate construction | Commercial borrower | Domestic loans | Commercial Real Estate business line | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	[2],[7]	0	11
Business loans | Real estate construction | Commercial borrower | Domestic loans | Commercial Real Estate business line | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	[3],[7]	0	0
Business loans | Real estate construction | Commercial borrower | Domestic loans | Commercial Real Estate business line | Nonaccrual
Financing Receivable, Recorded Investment [Line Items]
Total loans	[4],[7]	0	1
Business loans | Real estate construction | Commercial borrower | Domestic loans | Other business lines
Financing Receivable, Recorded Investment [Line Items]
Total loans	[9],[10]	320	349
Business loans | Real estate construction | Commercial borrower | Domestic loans | Other business lines | Pass
Financing Receivable, Recorded Investment [Line Items]
Total loans	[1],[9]	318	336
Business loans | Real estate construction | Commercial borrower | Domestic loans | Other business lines | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	[2],[9]	1	7
Business loans | Real estate construction | Commercial borrower | Domestic loans | Other business lines | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	[3],[9]	0	5
Business loans | Real estate construction | Commercial borrower | Domestic loans | Other business lines | Nonaccrual
Financing Receivable, Recorded Investment [Line Items]
Total loans	[4],[9]	1	1
Business loans | Real estate | Commercial borrower | Domestic loans
Financing Receivable, Recorded Investment [Line Items]
Total loans		8,977	8,604
Business loans | Real estate | Commercial borrower | Domestic loans | Pass
Financing Receivable, Recorded Investment [Line Items]
Total loans	[1]	8,567	8,086
Business loans | Real estate | Commercial borrower | Domestic loans | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	[2]	203	207
Business loans | Real estate | Commercial borrower | Domestic loans | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	[3]	147	216
Business loans | Real estate | Commercial borrower | Domestic loans | Nonaccrual
Financing Receivable, Recorded Investment [Line Items]
Total loans	[4]	60	95
Business loans | Real estate | Commercial borrower | Domestic loans | Commercial Real Estate business line
Financing Receivable, Recorded Investment [Line Items]
Total loans	[7],[8]	2,104	1,790
Business loans | Real estate | Commercial borrower | Domestic loans | Commercial Real Estate business line | Pass
Financing Receivable, Recorded Investment [Line Items]
Total loans	[1],[7]	2,031	1,652
Business loans | Real estate | Commercial borrower | Domestic loans | Commercial Real Estate business line | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	[2],[7]	31	69
Business loans | Real estate | Commercial borrower | Domestic loans | Commercial Real Estate business line | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	[3],[7]	26	47
Business loans | Real estate | Commercial borrower | Domestic loans | Commercial Real Estate business line | Nonaccrual
Financing Receivable, Recorded Investment [Line Items]
Total loans	[4],[7]	16	22
Business loans | Real estate | Commercial borrower | Domestic loans | Other business lines
Financing Receivable, Recorded Investment [Line Items]
Total loans	[9],[10]	6,873	6,814
Business loans | Real estate | Commercial borrower | Domestic loans | Other business lines | Pass
Financing Receivable, Recorded Investment [Line Items]
Total loans	[1],[9]	6,536	6,434
Business loans | Real estate | Commercial borrower | Domestic loans | Other business lines | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	[2],[9]	172	138
Business loans | Real estate | Commercial borrower | Domestic loans | Other business lines | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	[3],[9]	121	169
Business loans | Real estate | Commercial borrower | Domestic loans | Other business lines | Nonaccrual
Financing Receivable, Recorded Investment [Line Items]
Total loans	[4],[9]	44	73
Business loans | Lease financing | Commercial borrower | Domestic loans
Financing Receivable, Recorded Investment [Line Items]
Total loans		724	805
Business loans | Lease financing | Commercial borrower | Domestic loans | Pass
Financing Receivable, Recorded Investment [Line Items]
Total loans	[1]	693	778
Business loans | Lease financing | Commercial borrower | Domestic loans | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	[2]	17	26
Business loans | Lease financing | Commercial borrower | Domestic loans | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	[3]	8	1
Business loans | Lease financing | Commercial borrower | Domestic loans | Nonaccrual
Financing Receivable, Recorded Investment [Line Items]
Total loans	[4]	6	0
Retail loans
Financing Receivable, Recorded Investment [Line Items]
Total loans		4,355	4,213
Retail loans | Pass
Financing Receivable, Recorded Investment [Line Items]
Total loans	[1]	4,270	4,128
Retail loans | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	[2]	6	5
Retail loans | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	[3]	25	13
Retail loans | Nonaccrual
Financing Receivable, Recorded Investment [Line Items]
Total loans	[4]	54	67
Retail loans | Consumer borrower
Financing Receivable, Recorded Investment [Line Items]
Total loans		2,485	2,382
Retail loans | Consumer borrower | Pass
Financing Receivable, Recorded Investment [Line Items]
Total loans	[1]	2,442	2,338
Retail loans | Consumer borrower | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	[2]	4	3
Retail loans | Consumer borrower | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	[3]	12	10
Retail loans | Consumer borrower | Nonaccrual
Financing Receivable, Recorded Investment [Line Items]
Total loans	[4]	27	31
Retail loans | Real estate
Financing Receivable, Recorded Investment [Line Items]
Total loans		1,870	1,831
Retail loans | Real estate | Pass
Financing Receivable, Recorded Investment [Line Items]
Total loans	[1]	1,828	1,790
Retail loans | Real estate | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	[2]	2	2
Retail loans | Real estate | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	[3]	13	3
Retail loans | Real estate | Nonaccrual
Financing Receivable, Recorded Investment [Line Items]
Total loans	[4]	27	36
Retail loans | Home equity | Consumer borrower
Financing Receivable, Recorded Investment [Line Items]
Total loans		1,720	1,658
Retail loans | Home equity | Consumer borrower | Pass
Financing Receivable, Recorded Investment [Line Items]
Total loans	[1]	1,687	1,620
Retail loans | Home equity | Consumer borrower | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	[2]	1	0
Retail loans | Home equity | Consumer borrower | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	[3]	5	8
Retail loans | Home equity | Consumer borrower | Nonaccrual
Financing Receivable, Recorded Investment [Line Items]
Total loans	[4]	27	30
Retail loans | Other consumer | Consumer borrower
Financing Receivable, Recorded Investment [Line Items]
Total loans		765	724
Retail loans | Other consumer | Consumer borrower | Pass
Financing Receivable, Recorded Investment [Line Items]
Total loans	[1]	755	718
Retail loans | Other consumer | Consumer borrower | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	[2]	3	3
Retail loans | Other consumer | Consumer borrower | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	[3]	7	2
Retail loans | Other consumer | Consumer borrower | Nonaccrual
Financing Receivable, Recorded Investment [Line Items]
Total loans	[4]	$ 0	$ 1

[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. This category is generally consistent with the "special mention" category as defined 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 - Basis of Presentation and Accounting Policies. 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.

[7] Primarily loans to real estate developers.

[8] Primarily loans to real estate developers.

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

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