Asset Quality (Commercial Lending Asset Quality Indicators) (Details) - USD ($)	Jun. 30, 2015		Dec. 31, 2014		Jun. 30, 2014
Financing Receivable, Recorded Investment [Line Items]
Purchased impaired loans	$ 4,465,000,000		$ 4,858,000,000		$ 5,557,000,000
Total Loans	205,153,000,000	[1],[2]	204,817,000,000	[1],[2]	200,984,000,000
Total commercial lending [Member]
Financing Receivable, Recorded Investment [Line Items]
Purchased impaired loans	235,000,000		310,000,000		479,000,000
Total Loans	130,722,000,000		128,368,000,000		$ 124,083,000,000
Commercial [Member] | Total commercial lending [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans - Excluding Purchased Impaired Loans	98,083,000,000		97,347,000,000
Purchased impaired loans	50,000,000		74,000,000
Total Loans	98,133,000,000		97,420,000,000
Commercial Real Estate [Member] | Total commercial lending [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans - Excluding Purchased Impaired Loans	24,621,000,000		23,025,000,000
Purchased impaired loans	185,000,000		236,000,000
Total Loans	24,806,000,000		23,262,000,000
Equipment Lease Financing [Member] | Total commercial lending [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans - Excluding Purchased Impaired Loans	7,783,000,000		7,686,000,000
Total Loans	7,783,000,000		7,686,000,000
Pass [Member] | Total commercial lending [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	124,919,000,000		122,468,000,000
Pass [Member] | Commercial [Member] | Total commercial lending [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans - Excluding Purchased Impaired Loans	93,470,000,000		92,884,000,000
Pass [Member] | Commercial Real Estate [Member] | Total commercial lending [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans - Excluding Purchased Impaired Loans	23,828,000,000		22,066,000,000
Pass [Member] | Equipment Lease Financing [Member] | Total commercial lending [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans - Excluding Purchased Impaired Loans	7,621,000,000		7,518,000,000
Special Mention [Member] | Criticized Commercial Loans [Member] | Total commercial lending [Member]
Financing Receivable, Recorded Investment [Line Items]
Purchased impaired loans	6,000,000		4,000,000
Total Loans	2,153,000,000		2,346,000,000
Special Mention [Member] | Commercial [Member] | Criticized Commercial Loans [Member] | Total commercial lending [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans - Excluding Purchased Impaired Loans	1,848,000,000		1,984,000,000
Special Mention [Member] | Commercial Real Estate [Member] | Criticized Commercial Loans [Member] | Total commercial lending [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans - Excluding Purchased Impaired Loans	215,000,000		285,000,000
Special Mention [Member] | Equipment Lease Financing [Member] | Criticized Commercial Loans [Member] | Total commercial lending [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans - Excluding Purchased Impaired Loans	84,000,000		73,000,000
Substandard [Member] | Criticized Commercial Loans [Member] | Total commercial lending [Member]
Financing Receivable, Recorded Investment [Line Items]
Purchased impaired loans	208,000,000		280,000,000
Total Loans	3,544,000,000		3,436,000,000
Substandard [Member] | Commercial [Member] | Criticized Commercial Loans [Member] | Total commercial lending [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans - Excluding Purchased Impaired Loans	2,696,000,000		2,424,000,000
Substandard [Member] | Commercial Real Estate [Member] | Criticized Commercial Loans [Member] | Total commercial lending [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans - Excluding Purchased Impaired Loans	564,000,000		639,000,000
Substandard [Member] | Equipment Lease Financing [Member] | Criticized Commercial Loans [Member] | Total commercial lending [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans - Excluding Purchased Impaired Loans	76,000,000		93,000,000
Doubtful [Member] | Criticized Commercial Loans [Member] | Total commercial lending [Member]
Financing Receivable, Recorded Investment [Line Items]
Purchased impaired loans	21,000,000		26,000,000
Total Loans	106,000,000		118,000,000
Doubtful [Member] | Commercial [Member] | Criticized Commercial Loans [Member] | Total commercial lending [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans - Excluding Purchased Impaired Loans	69,000,000		55,000,000
Doubtful [Member] | Commercial Real Estate [Member] | Criticized Commercial Loans [Member] | Total commercial lending [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans - Excluding Purchased Impaired Loans	14,000,000		35,000,000
Doubtful [Member] | Equipment Lease Financing [Member] | Criticized Commercial Loans [Member] | Total commercial lending [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans - Excluding Purchased Impaired Loans	$ 2,000,000		$ 2,000,000

[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).