Asset Quality (Age Analysis of Past Due Accruing Loans) (Details) (USD $)	Jun. 30, 2013		Dec. 31, 2012		Jun. 30, 2012
Financing Receivable, Recorded Investment [Line Items]
Current or Less Than 30 Days Past Due	$ 176,578,000,000		$ 171,385,000,000
30-59 Days Past Due	686,000,000		919,000,000
60-89 Days Past Due	349,000,000		471,000,000
90 Days Or More Past Due	1,762,000,000		2,351,000,000
Total Past Due	2,797,000,000		3,741,000,000
Nonperforming loans	3,321,000,000		3,254,000,000
Fair Value Option Nonaccrual Loans	301,000,000		70,000,000
Purchased impaired loans	6,778,000,000		7,406,000,000		8,083,000,000
Total loans	189,775,000,000	[1],[2]	185,856,000,000	[1],[2]	180,425,000,000
Impact of alignment with interagency supervisory guidance - Accruing Consumer Loans Past Due	(395,000,000)
Current or Less Than 30 Days Past Due
Financing Receivable, Recorded Investment [Line Items]
Percentage of total loans	93.05%		92.21%
30-59 Days Past Due
Financing Receivable, Recorded Investment [Line Items]
Percentage of total loans	0.36%		0.49%
Impact of alignment with interagency supervisory guidance - Accruing Consumer Loans Past Due	(44,000,000)
60-89 Days Past Due
Financing Receivable, Recorded Investment [Line Items]
Percentage of total loans	0.18%		0.25%
Impact of alignment with interagency supervisory guidance - Accruing Consumer Loans Past Due	(36,000,000)
90 Days Or More Past Due
Financing Receivable, Recorded Investment [Line Items]
Percentage of total loans	0.93%		1.26%
Impact of alignment with interagency supervisory guidance - Accruing Consumer Loans Past Due	(315,000,000)
Total Past Due
Financing Receivable, Recorded Investment [Line Items]
Percentage of total loans	1.47%		2.00%
Nonperforming Loans
Financing Receivable, Recorded Investment [Line Items]
Percentage of total loans	1.75%		1.75%
Fair Value Option Nonaccrual Loans
Financing Receivable, Recorded Investment [Line Items]
Percentage of total loans	0.16%		0.05%
Purchased Impaired
Financing Receivable, Recorded Investment [Line Items]
Percentage of total loans	3.57%		3.99%
Total Loans
Financing Receivable, Recorded Investment [Line Items]
Percentage of total loans	100.00%		100.00%
Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Current or Less Than 30 Days Past Due	86,009,000,000		81,930,000,000
30-59 Days Past Due	85,000,000		115,000,000
60-89 Days Past Due	53,000,000		55,000,000
90 Days Or More Past Due	31,000,000		42,000,000
Total Past Due	169,000,000		212,000,000
Nonperforming loans	521,000,000		590,000,000
Purchased impaired loans	231,000,000		308,000,000
Total loans	86,930,000,000		83,040,000,000
Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Current or Less Than 30 Days Past Due	17,527,000,000		16,735,000,000
30-59 Days Past Due	66,000,000		100,000,000
60-89 Days Past Due	22,000,000		57,000,000
90 Days Or More Past Due			15,000,000
Total Past Due	88,000,000		172,000,000
Nonperforming loans	639,000,000		807,000,000
Purchased impaired loans	737,000,000		941,000,000
Total loans	18,991,000,000		18,655,000,000
Equipment Lease Financing [Member]
Financing Receivable, Recorded Investment [Line Items]
Current or Less Than 30 Days Past Due	7,336,000,000		7,214,000,000
30-59 Days Past Due	2,000,000		17,000,000
60-89 Days Past Due	4,000,000		1,000,000
90 Days Or More Past Due			2,000,000
Total Past Due	6,000,000		20,000,000
Nonperforming loans	7,000,000		13,000,000
Total loans	7,349,000,000		7,247,000,000
Home Equity [Member]
Financing Receivable, Recorded Investment [Line Items]
Current or Less Than 30 Days Past Due	32,707,000,000		32,174,000,000
30-59 Days Past Due	76,000,000		117,000,000
60-89 Days Past Due	29,000,000		58,000,000
Total Past Due	105,000,000		175,000,000
Nonperforming loans	1,131,000,000		951,000,000
Purchased impaired loans	2,473,000,000		2,620,000,000
Total loans	36,416,000,000		35,920,000,000
Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Current or Less Than 30 Days Past Due	8,464,000,000		8,464,000,000
30-59 Days Past Due	230,000,000		278,000,000
60-89 Days Past Due	108,000,000		146,000,000
90 Days Or More Past Due	1,376,000,000		1,901,000,000
Total Past Due	1,714,000,000		2,325,000,000
Nonperforming loans	962,000,000		845,000,000
Fair Value Option Nonaccrual Loans	301,000,000		70,000,000
Purchased impaired loans	3,336,000,000		3,536,000,000
Total loans	14,777,000,000		15,240,000,000
Residential Real Estate [Member] | 30-59 Days Past Due
Financing Receivable, Recorded Investment [Line Items]
Government insured or guaranteed loans included in past due loans	100,000,000		100,000,000
Residential Real Estate [Member] | 60-89 Days Past Due
Financing Receivable, Recorded Investment [Line Items]
Government insured or guaranteed loans included in past due loans	100,000,000		100,000,000
Residential Real Estate [Member] | 90 Days Or More Past Due
Financing Receivable, Recorded Investment [Line Items]
Government insured or guaranteed loans included in past due loans	1,300,000,000		1,900,000,000
Impact of alignment with interagency supervisory guidance - Accruing Consumer Loans Past Due	(295,000,000)
Credit Card [Member]
Financing Receivable, Recorded Investment [Line Items]
Current or Less Than 30 Days Past Due	4,052,000,000		4,205,000,000
30-59 Days Past Due	27,000,000		34,000,000
60-89 Days Past Due	19,000,000		23,000,000
90 Days Or More Past Due	33,000,000		36,000,000
Total Past Due	79,000,000		93,000,000
Nonperforming loans	4,000,000		5,000,000
Total loans	4,135,000,000		4,303,000,000
Other Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Current or Less Than 30 Days Past Due	20,483,000,000		20,663,000,000
30-59 Days Past Due	200,000,000		258,000,000
60-89 Days Past Due	114,000,000		131,000,000
90 Days Or More Past Due	322,000,000		355,000,000
Total Past Due	636,000,000		744,000,000
Nonperforming loans	57,000,000		43,000,000
Purchased impaired loans	1,000,000		1,000,000
Total loans	21,177,000,000		21,451,000,000
Other Consumer [Member] | 30-59 Days Past Due
Financing Receivable, Recorded Investment [Line Items]
Government insured or guaranteed loans included in past due loans	100,000,000		200,000,000
Other Consumer [Member] | 60-89 Days Past Due
Financing Receivable, Recorded Investment [Line Items]
Government insured or guaranteed loans included in past due loans	100,000,000		100,000,000
Other Consumer [Member] | 90 Days Or More Past Due
Financing Receivable, Recorded Investment [Line Items]
Government insured or guaranteed loans included in past due loans	$ 300,000,000		$ 300,000,000

[1] Amounts represent the assets or liabilities of consolidated variable interest entities (VIEs).

[2] Amounts represent items for which the Corporation has elected the fair value option.