LHFI Considered Impaired (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2012		Jun. 30, 2012		Dec. 31, 2011
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Interest Income, Cash Basis Method	$ 4		$ 8		$ 25
Unpaid Principal Balance	3,967		3,967		4,150
Amortized Cost	3,385	[1]	3,385	[1]	3,592	[2]
Related Allowance	381		381		448
Average Amortized Cost	3,426		3,456		3,751
Interest Income Recognized	32	[3]	64	[3]	132	[4]
Impaired Financing Receivables With No Related Allowance [Member] | Commercial Portfolio Segment [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	156		156		196
Amortized Cost	105	[1]	105	[1]	163	[2]
Related Allowance	0		0		0
Average Amortized Cost	124		133		212
Interest Income Recognized	1	[3]	1	[3]	5	[4]
Impaired Financing Receivables With No Related Allowance [Member] | Commercial Portfolio Segment [Member] | Commercial and Industrial
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	45		45		93
Amortized Cost	37	[1]	37	[1]	73	[2]
Related Allowance	0		0		0
Average Amortized Cost	37		38		109
Interest Income Recognized	0	[3]	0	[3]	3	[4]
Impaired Financing Receivables With No Related Allowance [Member] | Commercial Portfolio Segment [Member] | Commercial Real Estate
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	83		83		58
Amortized Cost	51	[1]	51	[1]	50	[2]
Related Allowance	0		0		0
Average Amortized Cost	59		63		56
Interest Income Recognized	1	[3]	1	[3]	1	[4]
Impaired Financing Receivables With No Related Allowance [Member] | Commercial Portfolio Segment [Member] | Commercial Construction [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	28		28		45
Amortized Cost	17	[1]	17	[1]	40	[2]
Related Allowance	0		0		0
Average Amortized Cost	28		32		47
Interest Income Recognized	0	[3]	0	[3]	1	[4]
Impaired Financing Receivables with Related Allowance [Member] | Commercial Portfolio Segment [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	250		250		319
Amortized Cost	213	[1]	213	[1]	249	[2]
Related Allowance	18		18		34
Average Amortized Cost	229		234		292
Interest Income Recognized	0	[3]	1	[3]	5	[4]
Impaired Financing Receivables with Related Allowance [Member] | Commercial Portfolio Segment [Member] | Commercial and Industrial
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	90		90		76
Amortized Cost	74	[1]	74	[1]	67	[2]
Related Allowance	7		7		9
Average Amortized Cost	81		83		68
Interest Income Recognized	0	[3]	0	[3]	1	[4]
Impaired Financing Receivables with Related Allowance [Member] | Commercial Portfolio Segment [Member] | Commercial Real Estate
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	92		92		111
Amortized Cost	76	[1]	76	[1]	82	[2]
Related Allowance	7		7		15
Average Amortized Cost	82		84		103
Interest Income Recognized	0	[3]	0	[3]	2	[4]
Impaired Financing Receivables with Related Allowance [Member] | Commercial Portfolio Segment [Member] | Commercial Construction [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	68		68		132
Amortized Cost	63	[1]	63	[1]	100	[2]
Related Allowance	4		4		10
Average Amortized Cost	66		67		121
Interest Income Recognized	0	[3]	1	[3]	2	[4]
Impaired Financing Receivables with Related Allowance [Member] | Residential Portfolio Segment [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	3,510		3,510		3,596
Amortized Cost	3,016	[1]	3,016	[1]	3,141	[2]
Related Allowance	355		355		405
Average Amortized Cost	3,022		3,036		3,208
Interest Income Recognized	30	[3]	60	[3]	119	[4]
Impaired Financing Receivables with Related Allowance [Member] | Residential Portfolio Segment [Member] | Residential Nonguaranteed [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	2,659		2,659		2,797
Amortized Cost	2,255	[1]	2,255	[1]	2,405	[2]
Related Allowance	238		238		293
Average Amortized Cost	2,255		2,260		2,451
Interest Income Recognized	20	[3]	42	[3]	88	[4]
Impaired Financing Receivables with Related Allowance [Member] | Residential Portfolio Segment [Member] | Home Equity
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	577		577		553
Amortized Cost	534	[1]	534	[1]	515	[2]
Related Allowance	92		92		86
Average Amortized Cost	535		539		528
Interest Income Recognized	7	[3]	13	[3]	23	[4]
Impaired Financing Receivables with Related Allowance [Member] | Residential Portfolio Segment [Member] | Residential Construction
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	274		274		246
Amortized Cost	227	[1]	227	[1]	221	[2]
Related Allowance	25		25		26
Average Amortized Cost	232		237		229
Interest Income Recognized	3	[3]	5	[3]	8	[4]
Impaired Financing Receivables with Related Allowance [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	51		51		39
Amortized Cost	51	[1]	51	[1]	39	[2]
Related Allowance	8		8		9
Average Amortized Cost	51		53		39
Interest Income Recognized	1	[3]	2	[3]	3	[4]
Impaired Financing Receivables with Related Allowance [Member] | Consumer Portfolio Segment [Member] | Consumer Other Direct
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	12		12		12
Amortized Cost	12	[1]	12	[1]	12	[2]
Related Allowance	1		1		1
Average Amortized Cost	12		12		13
Interest Income Recognized	0	[3]	0	[3]	1	[4]
Impaired Financing Receivables with Related Allowance [Member] | Consumer Portfolio Segment [Member] | Consumer Indirect
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	14		14
Amortized Cost	14	[1]	14	[1]
Related Allowance	0		0
Average Amortized Cost	14		15
Interest Income Recognized	1	[3]	1	[3]
Impaired Financing Receivables with Related Allowance [Member] | Consumer Portfolio Segment [Member] | Consumer Credit Card
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	25		25		27
Amortized Cost	25	[1]	25	[1]	27	[2]
Related Allowance	7		7		8
Average Amortized Cost	25		26		26
Interest Income Recognized	$ 0	[3]	$ 1	[3]	$ 2	[4]

[1] Amortized cost reflects charge-offs that have been recognized plus other amounts that have been applied to reduce the net book balance.

[2] Amortized cost reflects charge-offs that have been recognized plus other amounts that have been applied to reduce net book balance.

[3] Of the interest income recognized for the three and six months ended June 30, 2012, cash basis interest income was $4 million and $8 million, respectively.

[4] Of the interest income recognized for the year ended December 31, 2011, cash basis interest income was $25 million.