Allowance For Credit Losses (Details 1) (USD $) In Millions, unless otherwise specified	3 Months Ended			6 Months Ended
	Jun. 30, 2012		Jun. 30, 2011	Jun. 30, 2012		Jun. 30, 2011	Dec. 31, 2011
Changes in the allowance for credit losses by product and the related loan
Balance at beginning of period	$ 603		$ 771	$ 743	[1]	$ 852
Provision for credit losses	89		95	89		93
Charge-offs	(91)		(133)	(253)		(225)
Recoveries	18		14	40		27
Net charge offs	(73)		(119)	(213)		(198)
Ending balance: collectively evaluated for impairment	384		472	384		472
Ending balance: individually evaluated for impairment	235		275	235		275
Balance at end of period	619	[1]	747	619	[1]	747
Loans:
Collectively evaluated for impairment	53,610		47,291	53,610		47,291
Individually evaluated for impairment	1,599		1,543	1,599		1,543
Loans carried at the lower of amortized cost or fair value less cost to sell	855		778	855		778
Total loans	56,064	[1]	49,612	56,064	[1]	49,612	51,867	[1]
Commercial Loan [Member]
Loans:
Total loans	37,417			37,417			33,649
Commercial Loan [Member] | Construction and other real estate [Member]
Changes in the allowance for credit losses by product and the related loan
Balance at beginning of period	205		217	212		243
Provision for credit losses	(5)		49	(25)		21
Charge-offs	(2)		(39)	(3)		(43)
Recoveries			2	14		8
Net charge offs	(2)		(37)	11		(35)
Ending balance: collectively evaluated for impairment	87		120	87		120
Ending balance: individually evaluated for impairment	111		109	111		109
Balance at end of period	198		229	198		229
Loans:
Collectively evaluated for impairment	7,386		7,213	7,386		7,213
Individually evaluated for impairment	591		698	591		698
Total loans	7,977		7,911	7,977		7,911	7,860
Commercial Loan [Member] | Business banking and middle markets enterprises [Member]
Changes in the allowance for credit losses by product and the related loan
Balance at beginning of period	76		119	78		132
Provision for credit losses	15		(8)	21		(9)
Charge-offs	(13)		(19)	(23)		(33)
Recoveries	2		4	4		6
Net charge offs	(11)		(15)	(19)		(27)
Ending balance: collectively evaluated for impairment	73		79	73		79
Ending balance: individually evaluated for impairment	7		17	7		17
Balance at end of period	80		96	80		96
Loans:
Collectively evaluated for impairment	11,141		8,475	11,141		8,475
Individually evaluated for impairment	115		156	115		156
Total loans	11,256		8,631	11,256		8,631	10,225
Commercial Loan [Member] | Global banking [Member]
Changes in the allowance for credit losses by product and the related loan
Balance at beginning of period	25		111	131		116
Provision for credit losses	19		(1)	(3)		(6)
Charge-offs				(84)
Net charge offs				(84)
Ending balance: collectively evaluated for impairment	31		39	31		39
Ending balance: individually evaluated for impairment	13		71	13		71
Balance at end of period	44		110	44		110
Loans:
Collectively evaluated for impairment	14,928		10,529	14,928		10,529
Individually evaluated for impairment	114		74	114		74
Total loans	15,042		10,603	15,042		10,603	12,658
Commercial Loan [Member] | Other commercial [Member]
Changes in the allowance for credit losses by product and the related loan
Balance at beginning of period	20		23	21		32
Provision for credit losses	(7)			(9)		(10)
Charge-offs			(2)			(2)
Recoveries	5			6		1
Net charge offs	5		(2)	6		(1)
Ending balance: collectively evaluated for impairment	17		17	17		17
Ending balance: individually evaluated for impairment	1		4	1		4
Balance at end of period	18		21	18		21
Loans:
Collectively evaluated for impairment	3,055		2,547	3,055		2,547
Individually evaluated for impairment	87		101	87		101
Total loans	3,142		2,648	3,142		2,648	2,906
Commercial Loan [Member] | Residential mortgages, excluding home equity mortgages [Member]
Changes in the allowance for credit losses by product and the related loan
Balance at beginning of period	182		161	192		167
Provision for credit losses	24		27	39		46
Charge-offs	(23)		(28)	(49)		(54)
Recoveries	5		2	6		3
Net charge offs	(18)		(26)	(43)		(51)
Ending balance: collectively evaluated for impairment	95		99	95		99
Ending balance: individually evaluated for impairment	93		63	93		63
Balance at end of period	188		162	188		162
Loans:
Collectively evaluated for impairment	13,243		12,840	13,243		12,840
Individually evaluated for impairment	660		482	660		482
Loans carried at the lower of amortized cost or fair value less cost to sell	855		778	855		778
Total loans	14,758		14,100	14,758		14,100
Consumer Loan [Member]
Loans:
Total loans	18,647			18,647			18,218
Consumer Loan [Member] | Home equity mortgages [Member]
Changes in the allowance for credit losses by product and the related loan
Balance at beginning of period	43		68	52		77
Provision for credit losses	34		12	42		23
Charge-offs	(30)		(18)	(47)		(38)
Net charge offs	(30)		(18)	(47)		(38)
Ending balance: collectively evaluated for impairment	43		58	43		58
Ending balance: individually evaluated for impairment	4		4	4		4
Balance at end of period	47		62	47		62
Loans:
Collectively evaluated for impairment	2,441		3,598	2,441		3,598
Individually evaluated for impairment	14		9	14		9
Total loans	2,455		3,607	2,455		3,607	2,563
Consumer Loan [Member] | Credit cards [Member]
Changes in the allowance for credit losses by product and the related loan
Balance at beginning of period	35		48	39		58
Provision for credit losses	9		12	20		20
Charge-offs	(16)		(19)	(33)		(40)
Recoveries	3		3	5		6
Net charge offs	(13)		(16)	(28)		(34)
Ending balance: collectively evaluated for impairment	25		37	25		37
Ending balance: individually evaluated for impairment	6		7	6		7
Balance at end of period	31		44	31		44
Loans:
Collectively evaluated for impairment	765		1,164	765		1,164
Individually evaluated for impairment	18		23	18		23
Total loans	783		1,187	783		1,187	828
Consumer Loan [Member] | Other consumer [Member]
Changes in the allowance for credit losses by product and the related loan
Balance at beginning of period	17		24	18		27
Provision for credit losses			4	4		8
Charge-offs	(7)		(8)	(14)		(15)
Recoveries	3		3	5		3
Net charge offs	(4)		(5)	(9)		(12)
Ending balance: collectively evaluated for impairment	13		23	13		23
Balance at end of period	13		23	13		23
Loans:
Collectively evaluated for impairment	0		925	0		925
Total loans	$ 651		$ 925	$ 651		$ 925	$ 714

[1] The following table summarizes assets and liabilities related to variable interest entities ("VIEs") as of June 30, 2012 and December 31, 2011 which are consolidated on our balance sheet. Assets and liabilities exclude intercompany balances that eliminate in consolidation.