Asset Quality (Home Equity and Residential Real Estate Balances) (Details) - USD ($)	Jun. 30, 2015		Dec. 31, 2014		Jun. 30, 2014
Financing Receivable, Recorded Investment [Line Items]
Purchased Impaired Loans - Outstanding Balance	$ 4,482,000,000		$ 5,007,000,000
Total loans	205,153,000,000	[1],[2]	204,817,000,000	[1],[2]	$ 200,984,000,000
Total home equity and residential real estate loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans - Excluding Purchased Impaired Loans	42,830,000,000		43,348,000,000
Purchased Impaired Loans - Outstanding Balance	4,136,000,000		4,541,000,000
Government insured or guaranteed residential real estate mortgages	1,007,000,000		1,188,000,000
Purchase accounting adjustments - purchased impaired loans	94,000,000		7,000,000
Total loans	$ 48,067,000,000		$ 49,084,000,000

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

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