LHFI Considered Impaired (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		12 Months Ended
	Mar. 31, 2012		Dec. 31, 2011
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	$ 3,952		$ 4,150
Amortized Cost	3,411	[1]	3,592	[2]
Related Allowance	400		448
Average Amortized Cost	3,439		3,751
Interest Income Recognized	32	[3]	132	[4]
Impaired Financing Receivables With No Related Allowance [Member] | Commercial Portfolio Segment
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	110		196
Amortized Cost	83	[1]	163	[2]
Related Allowance	0		0
Average Amortized Cost	87		212
Interest Income Recognized	0	[3]	5	[4]
Impaired Financing Receivables With No Related Allowance [Member] | Commercial Portfolio Segment | Commercial and Industrial
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	30		93
Amortized Cost	26	[1]	73	[2]
Related Allowance	0		0
Average Amortized Cost	28		109
Interest Income Recognized	0	[3]	3	[4]
Impaired Financing Receivables With No Related Allowance [Member] | Commercial Portfolio Segment | Commercial Real Estate
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	59		58
Amortized Cost	41	[1]	50	[2]
Related Allowance	0		0
Average Amortized Cost	42		56
Interest Income Recognized	0	[3]	1	[4]
Impaired Financing Receivables With No Related Allowance [Member] | Commercial Portfolio Segment | Commercial Construction
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	21		45
Amortized Cost	16	[1]	40	[2]
Related Allowance	0		0
Average Amortized Cost	17		47
Interest Income Recognized	0	[3]	1	[4]
Impaired Financing Receivables with Related Allowance [Member] | Commercial Portfolio Segment
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	277		319
Amortized Cost	238	[1]	249	[2]
Related Allowance	16		34
Average Amortized Cost	249		292
Interest Income Recognized	1	[3]	5	[4]
Impaired Financing Receivables with Related Allowance [Member] | Commercial Portfolio Segment | Commercial and Industrial
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	83		76
Amortized Cost	75	[1]	67	[2]
Related Allowance	7		9
Average Amortized Cost	75		68
Interest Income Recognized	0	[3]	1	[4]
Impaired Financing Receivables with Related Allowance [Member] | Commercial Portfolio Segment | Commercial Real Estate
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	102		111
Amortized Cost	83	[1]	82	[2]
Related Allowance	6		15
Average Amortized Cost	90		103
Interest Income Recognized	0	[3]	2	[4]
Impaired Financing Receivables with Related Allowance [Member] | Commercial Portfolio Segment | Commercial Construction
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	92		132
Amortized Cost	80	[1]	100	[2]
Related Allowance	3		10
Average Amortized Cost	84		121
Interest Income Recognized	1	[3]	2	[4]
Impaired Financing Receivables with Related Allowance [Member] | Residential Mortgage Loans
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	3,527		3,596
Amortized Cost	3,052	[1]	3,141	[2]
Related Allowance	376		405
Average Amortized Cost	3,064		3,208
Interest Income Recognized	30	[3]	119	[4]
Impaired Financing Receivables with Related Allowance [Member] | Residential Mortgage Loans | Residential Nonguaranteed
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	2,707		2,797
Amortized Cost	2,313	[1]	2,405	[2]
Related Allowance	261		293
Average Amortized Cost	2,319		2,451
Interest Income Recognized	22	[3]	88	[4]
Impaired Financing Receivables with Related Allowance [Member] | Residential Mortgage Loans | Home Equity
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	561		553
Amortized Cost	518	[1]	515	[2]
Related Allowance	90		86
Average Amortized Cost	521		528
Interest Income Recognized	6	[3]	23	[4]
Impaired Financing Receivables with Related Allowance [Member] | Residential Mortgage Loans | Residential Construction
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	259		246
Amortized Cost	221	[1]	221	[2]
Related Allowance	25		26
Average Amortized Cost	224		229
Interest Income Recognized	2	[3]	8	[4]
Impaired Financing Receivables with Related Allowance [Member] | Consumer Portfolio Segment
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	38		39
Amortized Cost	38	[1]	39	[2]
Related Allowance	8		9
Average Amortized Cost	39		39
Interest Income Recognized	1	[3]	3	[4]
Impaired Financing Receivables with Related Allowance [Member] | Consumer Portfolio Segment | Consumer Other Direct
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	12		12
Amortized Cost	12	[1]	12	[2]
Related Allowance	1		1
Average Amortized Cost	12		13
Interest Income Recognized	0	[3]	1	[4]
Impaired Financing Receivables with Related Allowance [Member] | Consumer Portfolio Segment | Consumer Credit Card
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	26		27
Amortized Cost	26	[1]	27	[2]
Related Allowance	7		8
Average Amortized Cost	27		26
Interest Income Recognized	$ 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 months ended March 31, 2012, cash basis interest income was $4 million.

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