Asset Quality (Age Analysis of Past Due Accruing Loans) (Details) (USD $)	Sep. 30, 2012		Dec. 31, 2011		Sep. 30, 2011
Financing Receivable, Recorded Investment [Line Items]
Current or Less Than 30 Days Past Due	$ 166,820,000,000		$ 144,249,000,000
30-59 Days Past Due	883,000,000		1,018,000,000
60-89 Days Past Due	542,000,000		547,000,000
90 Days Or More Past Due	2,456,000,000		2,973,000,000
Total Past Due	3,881,000,000		4,538,000,000
Nonperforming loans	3,414,000,000		3,560,000,000
Purchased impaired loans	7,749,000,000		6,667,000,000		6,927,000,000
Total loans	181,864,000,000	[1],[2],[3],[4]	159,014,000,000	[1],[2],[3],[4]	154,543,000,000
Current or Less Than 30 Days Past Due
Financing Receivable, Recorded Investment [Line Items]
Percentage of total loans	91.72%		90.72%
30-59 Days Past Due
Financing Receivable, Recorded Investment [Line Items]
Percentage of total loans	0.49%		0.64%
60-89 Days Past Due
Financing Receivable, Recorded Investment [Line Items]
Percentage of total loans	0.30%		0.34%
90 Days Or More Past Due
Financing Receivable, Recorded Investment [Line Items]
Percentage of total loans	1.35%		1.87%
Total Past Due [Member]
Financing Receivable, Recorded Investment [Line Items]
Percentage of total loans	2.14%		2.85%
Nonperforming Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Percentage of total loans	1.88%		2.24%
Purchased Impaired [Member]
Financing Receivable, Recorded Investment [Line Items]
Percentage of total loans	4.26%		4.19%
Total Loans [Member]
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	78,291,000,000		64,437,000,000
30-59 Days Past Due	141,000,000		122,000,000
60-89 Days Past Due	92,000,000		47,000,000
90 Days Or More Past Due	41,000,000		49,000,000
Total Past Due	274,000,000		218,000,000
Nonperforming loans	749,000,000		899,000,000
Purchased impaired loans	354,000,000		140,000,000
Total loans	79,668,000,000		65,694,000,000
Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Current or Less Than 30 Days Past Due	16,368,000,000		14,010,000,000
30-59 Days Past Due	91,000,000		96,000,000
60-89 Days Past Due	66,000,000		35,000,000
90 Days Or More Past Due	36,000,000		6,000,000
Total Past Due	193,000,000		137,000,000
Nonperforming loans	1,000,000,000		1,345,000,000
Purchased impaired loans	1,048,000,000		712,000,000
Total loans	18,609,000,000		16,204,000,000
Equipment Lease Financing [Member]
Financing Receivable, Recorded Investment [Line Items]
Current or Less Than 30 Days Past Due	6,894,000,000		6,367,000,000
30-59 Days Past Due	8,000,000		22,000,000
60-89 Days Past Due	5,000,000		5,000,000
90 Days Or More Past Due	1,000,000
Total Past Due	14,000,000		27,000,000
Nonperforming loans	15,000,000		22,000,000
Total loans	6,923,000,000		6,416,000,000
Home Equity [Member]
Financing Receivable, Recorded Investment [Line Items]
Current or Less Than 30 Days Past Due	32,166,000,000		29,288,000,000
30-59 Days Past Due	130,000,000		173,000,000
60-89 Days Past Due	69,000,000		114,000,000
90 Days Or More Past Due			221,000,000
Total Past Due	199,000,000		508,000,000
Nonperforming loans	818,000,000		529,000,000
Purchased impaired loans	2,695,000,000		2,764,000,000
Total loans	35,878,000,000		33,089,000,000
Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Current or Less Than 30 Days Past Due	8,530,000,000		7,935,000,000
30-59 Days Past Due	274,000,000		302,000,000
60-89 Days Past Due	146,000,000		176,000,000
90 Days Or More Past Due	1,993,000,000		2,281,000,000
Total Past Due	2,413,000,000		2,759,000,000
Nonperforming loans	790,000,000		726,000,000
Purchased impaired loans	3,650,000,000		3,049,000,000
Total loans	15,383,000,000		14,469,000,000
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	1,900,000,000		2,100,000,000
Credit Card [Member]
Financing Receivable, Recorded Investment [Line Items]
Current or Less Than 30 Days Past Due	4,047,000,000		3,857,000,000
30-59 Days Past Due	31,000,000		38,000,000
60-89 Days Past Due	20,000,000		25,000,000
90 Days Or More Past Due	32,000,000		48,000,000
Total Past Due	83,000,000		111,000,000
Nonperforming loans	5,000,000		8,000,000
Total loans	4,135,000,000		3,976,000,000
Other Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Current or Less Than 30 Days Past Due	20,524,000,000		18,355,000,000
30-59 Days Past Due	208,000,000		265,000,000
60-89 Days Past Due	144,000,000		145,000,000
90 Days Or More Past Due	353,000,000		368,000,000
Total Past Due	705,000,000		778,000,000
Nonperforming loans	37,000,000		31,000,000
Purchased impaired loans	2,000,000		2,000,000
Total loans	21,268,000,000		19,166,000,000
Other Consumer [Member] | 30-59 Days Past Due
Financing Receivable, Recorded Investment [Line Items]
Government insured or guaranteed loans included in past due loans	200,000,000		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.

[3] Net of unearned income, net deferred loan fees, unamortized discounts and premiums, and purchase discounts and premiums totaling $2.9 billion and $2.3 billion atSeptember 30, 2012 and December 31, 2011, respectively.

[4] Future accretable yield related to purchased impaired loans is not included in loans outstanding.