Allowances for Loan and Lease Losses and Unfunded Loan Commitments and Letters of Credit (Rollforward of Allowance For Loan and Lease Losses and Associated Loan Data) (Details) (USD $)	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	$ 3,609,000,000	[1]	$ 4,036,000,000		$ 4,347,000,000
Charge-offs	(1,021,000,000)		(1,588,000,000)		(1,870,000,000)
Recoveries	490,000,000		511,000,000		581,000,000
Net charge-offs	(531,000,000)		(1,077,000,000)		(1,289,000,000)
Provision For Credit Losses	273,000,000		643,000,000		987,000,000
Net change in allowance for unfunded loan commitments and letters of credit	(17,000,000)		8,000,000		(10,000,000)
Other	(3,000,000)		(1,000,000)		1,000,000
Ending Balance	3,331,000,000	[1]	3,609,000,000	[1]	4,036,000,000
TDRs individually evaluated for impairment - associated allowance	386,000,000		470,000,000		587,000,000
Other loans individually evaluated for impairment - associated allowance	77,000,000		155,000,000		253,000,000
Loans collectively evaluated for impairment - associated allowance	1,996,000,000		1,980,000,000		2,099,000,000
Purchased impaired loans - associated allowance	872,000,000		1,004,000,000		1,097,000,000
TDRs individually evaluated for impairment	2,583,000,000		2,739,000,000		2,859,000,000
Other loans individually evaluated for impairment	309,000,000		649,000,000		1,057,000,000
Loans collectively evaluated for impairment	196,033,000,000		184,969,000,000		174,109,000,000
Fair value option loans	1,034,000,000		1,150,000,000		425,000,000
Purchased impaired loans	4,858,000,000		6,106,000,000		7,406,000,000
Total loans	204,817,000,000	[1],[2]	195,613,000,000	[1],[2]	185,856,000,000
Portfolio segment ALLL as a percentage of total ALLL	100.00%		100.00%		100.00%
Ratio of the allowance for loan and lease losses to total loans	1.63%		1.84%		2.17%
Impact of alignment with interagency guidance - Additional chargeoffs taken			134,000,000
Evaluated for impairment based upon collateral values
Financing Receivable Allowance For Credit Losses [Line Items]
Loans collectively evaluated for impairment	195,000,000		252,000,000
Total commercial lending [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	1,547,000,000		1,774,000,000		1,995,000,000
Charge-offs	(360,000,000)		(606,000,000)		(804,000,000)
Recoveries	305,000,000		357,000,000		445,000,000
Net charge-offs	(55,000,000)		(249,000,000)		(359,000,000)
Provision For Credit Losses	100,000,000		36,000,000		138,000,000
Net change in allowance for unfunded loan commitments and letters of credit	(18,000,000)		(13,000,000)		(1,000,000)
Other	(3,000,000)		(1,000,000)		1,000,000
Ending Balance	1,571,000,000		1,547,000,000		1,774,000,000
TDRs individually evaluated for impairment - associated allowance	62,000,000		24,000,000		40,000,000
Other loans individually evaluated for impairment - associated allowance	77,000,000		155,000,000		253,000,000
Loans collectively evaluated for impairment - associated allowance	1,353,000,000		1,235,000,000		1,242,000,000
Purchased impaired loans - associated allowance	79,000,000		133,000,000		239,000,000
TDRs individually evaluated for impairment	542,000,000		578,000,000		541,000,000
Other loans individually evaluated for impairment	309,000,000		649,000,000		1,057,000,000
Loans collectively evaluated for impairment	127,207,000,000		115,245,000,000		106,095,000,000
Purchased impaired loans	310,000,000		673,000,000		1,249,000,000
Total loans	128,368,000,000		117,145,000,000		108,942,000,000
Portfolio segment ALLL as a percentage of total ALLL	47.00%		43.00%		44.00%
Ratio of the allowance for loan and lease losses to total loans	1.22%		1.32%		1.63%
Total consumer lending [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	2,062,000,000		2,262,000,000		2,352,000,000
Charge-offs	(661,000,000)		(982,000,000)		(1,066,000,000)
Recoveries	185,000,000		154,000,000		136,000,000
Net charge-offs	(476,000,000)		(828,000,000)		(930,000,000)
Provision For Credit Losses	173,000,000		607,000,000		849,000,000
Net change in allowance for unfunded loan commitments and letters of credit	1,000,000		21,000,000		(9,000,000)
Ending Balance	1,760,000,000		2,062,000,000		2,262,000,000
TDRs individually evaluated for impairment - associated allowance	324,000,000		446,000,000		547,000,000
Loans collectively evaluated for impairment - associated allowance	643,000,000		745,000,000		857,000,000
Purchased impaired loans - associated allowance	793,000,000		871,000,000		858,000,000
TDRs individually evaluated for impairment	2,041,000,000		2,161,000,000		2,318,000,000
Loans collectively evaluated for impairment	68,826,000,000		69,724,000,000		68,014,000,000
Fair value option loans	1,034,000,000		1,150,000,000		425,000,000
Purchased impaired loans	4,548,000,000		5,433,000,000		6,157,000,000
Total loans	$ 76,449,000,000		$ 78,468,000,000		$ 76,914,000,000
Portfolio segment ALLL as a percentage of total ALLL	53.00%		57.00%		56.00%
Ratio of the allowance for loan and lease losses to total loans	2.30%		2.63%		2.94%

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

[2] Amounts represent items for which we have elected the fair value option.