Loans - TDR Activity Rollforward (Details 4a) (USD $) In Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2011	Sep. 30, 2011
Commercial Portfolio Segment [Member]
Loans Modified in TDRs [Roll Forward]
Beginning balance of TDRs	$ 1,000	$ 1,143
New TDRs	123	771
Increases to Existing TDRs	0	23
Charge-offs post-modification	(14)	(162)
Principal payments, sales and other	(181)	(847)
Ending balance of TDRs	928	928
Commercial Portfolio Segment [Member] | Commercial and industrial [Member]
Loans Modified in TDRs [Roll Forward]
Beginning balance of TDRs	683	212
New TDRs	60	642
Increases to Existing TDRs	0	19
Charge-offs post-modification	(13)	(19)
Principal payments, sales and other	(105)	(229)
Ending balance of TDRs	625	625
Commercial Portfolio Segment [Member] | Real Estate [Member]
Loans Modified in TDRs [Roll Forward]
Beginning balance of TDRs	289	907
New TDRs	43	103
Increases to Existing TDRs	0	4
Charge-offs post-modification	(1)	(143)
Principal payments, sales and other	(70)	(610)
Ending balance of TDRs	261	261
Commercial Portfolio Segment [Member] | Financial Institutions, Government Agencies and Other Wholesale [Member]
Loans Modified in TDRs [Roll Forward]
Beginning balance of TDRs	28	24
New TDRs	20	26
Increases to Existing TDRs	0	0
Charge-offs post-modification	0	0
Principal payments, sales and other	(6)	(8)
Ending balance of TDRs	42	42
Consumer Portfolio Segment | Residential real estate, excluding PCI [Member]
Loans Modified in TDRs [Roll Forward]
Beginning balance of TDRs	7,011	5,344
New TDRs	1,525	3,650
Charge-offs post-modification	(93)	(301)
Foreclosures and other liquidations	(54)	(133)
Principal payments, sales and other	(125)	(296)
Ending balance of TDRs	8,264	8,264
Consumer Portfolio Segment | Home Equity Senior Lien [Member]
Loans Modified in TDRs [Roll Forward]
Beginning balance of TDRs	261	226
New TDRs	21	67
Charge-offs post-modification	(2)	(8)
Foreclosures and other liquidations	0	0
Principal payments, sales and other	(5)	(10)
Ending balance of TDRs	275	275
Consumer Portfolio Segment | Home Equity Junior Lien [Member]
Loans Modified in TDRs [Roll Forward]
Beginning balance of TDRs	517	283
New TDRs	117	410
Charge-offs post-modification	(13)	(48)
Foreclosures and other liquidations	(1)	(6)
Principal payments, sales and other	(14)	(33)
Ending balance of TDRs	606	606
Consumer Portfolio Segment | Prime Mortgages, including option ARMs [Member]
Loans Modified in TDRs [Roll Forward]
Beginning balance of TDRs	3,390	2,084
New TDRs	1,116	2,614
Charge-offs post-modification	(24)	(77)
Foreclosures and other liquidations	(28)	(67)
Principal payments, sales and other	(78)	(178)
Ending balance of TDRs	4,376	4,376
Consumer Portfolio Segment | Subprime Mortgage [Member]
Loans Modified in TDRs [Roll Forward]
Beginning balance of TDRs	2,843	2,751
New TDRs	271	559
Charge-offs post-modification	(54)	(168)
Foreclosures and other liquidations	(25)	(60)
Principal payments, sales and other	(28)	(75)
Ending balance of TDRs	3,007	3,007
Consumer Portfolio Segment | Other Consumer [Member]
Loans Modified in TDRs [Roll Forward]
Beginning balance of TDRs	517	486
New TDRs	61	204
Charge-offs post-modification	(6)	(11)
Foreclosures and other liquidations	(1)	(3)
Principal payments, sales and other	(55)	(160)
Ending balance of TDRs	516	516
Consumer Portfolio Segment | Consumer Loans Auto Financing Receivable [Member]
Loans Modified in TDRs [Roll Forward]
Beginning balance of TDRs	88	91
New TDRs	13	38
Charge-offs post-modification	(1)	(4)
Foreclosures and other liquidations	0	0
Principal payments, sales and other	(14)	(39)
Ending balance of TDRs	86	86
Consumer Portfolio Segment | Consumer business banking
Loans Modified in TDRs [Roll Forward]
Beginning balance of TDRs	429	395
New TDRs	48	166
Charge-offs post-modification	(5)	(7)
Foreclosures and other liquidations	(1)	(3)
Principal payments, sales and other	(41)	(121)
Ending balance of TDRs	$ 430	$ 430