Asset Quality (Commercial Lending Asset Quality Indicators) (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2014		Dec. 31, 2013		Jun. 30, 2013
Financing Receivable, Recorded Investment [Line Items]
Purchased impaired loans	$ 5,557		$ 6,106		$ 6,778
Total Loans	200,984	[1],[2]	195,613	[1],[2]	189,775
Total commercial lending [Member]
Financing Receivable, Recorded Investment [Line Items]
Purchased impaired loans					968
Total Loans	124,083		117,145		113,270
Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Purchased impaired loans	109		157
Total Loans	93,536		88,378
Commercial [Member] | Total commercial lending [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans - Excluding Purchased Impaired Loans	93,427		88,221
Total Loans	93,536		88,378
Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Purchased impaired loans	370		516
Total Loans	22,919		21,191
Commercial Real Estate [Member] | Total commercial lending [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans - Excluding Purchased Impaired Loans	22,549		20,675
Total Loans	22,919		21,191
Equipment Lease Financing [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	7,628		7,576
Equipment Lease Financing [Member] | Total commercial lending [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans - Excluding Purchased Impaired Loans	7,628		7,576
Total Loans	7,628		7,576
Purchased Impaired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Purchased impaired loans	5,557		6,106
Purchased Impaired Loans [Member] | Total commercial lending [Member]
Financing Receivable, Recorded Investment [Line Items]
Purchased impaired loans	479		673
Pass [Member] | Total commercial lending [Member]
Financing Receivable, Recorded Investment [Line Items]
Purchased impaired loans			10
Total Loans	118,021		110,491
Pass [Member] | Commercial [Member] | Total commercial lending [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans - Excluding Purchased Impaired Loans	89,158		83,903
Pass [Member] | Commercial Real Estate [Member] | Total commercial lending [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans - Excluding Purchased Impaired Loans	21,393		19,175
Pass [Member] | Equipment Lease Financing [Member] | Total commercial lending [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans - Excluding Purchased Impaired Loans	7,470		7,403
Special Mention [Member] | Criticized Commercial Loans [Member] | Total commercial lending [Member]
Financing Receivable, Recorded Investment [Line Items]
Purchased impaired loans	28		31
Total Loans	2,104		2,303
Special Mention [Member] | Commercial [Member] | Criticized Commercial Loans [Member] | Total commercial lending [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans - Excluding Purchased Impaired Loans	1,794		1,894
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	212		301
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	70		77
Substandard [Member] | Criticized Commercial Loans [Member] | Total commercial lending [Member]
Financing Receivable, Recorded Investment [Line Items]
Purchased impaired loans	380		469
Total Loans	3,752		4,027
Substandard [Member] | Commercial [Member] | Criticized Commercial Loans [Member] | Total commercial lending [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans - Excluding Purchased Impaired Loans	2,394		2,352
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	893		1,113
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	85		93
Doubtful [Member] | Criticized Commercial Loans [Member] | Total commercial lending [Member]
Financing Receivable, Recorded Investment [Line Items]
Purchased impaired loans	71		163
Total Loans	206		324
Doubtful [Member] | Commercial [Member] | Criticized Commercial Loans [Member] | Total commercial lending [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans - Excluding Purchased Impaired Loans	81		72
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	51		86
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	$ 3		$ 3

[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.