LHFI Considered Impaired (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2013		Jun. 30, 2012		Jun. 30, 2013		Jun. 30, 2012		Dec. 31, 2012
Financing Receivable, Impaired [Line Items]
PrincipalForgivenessRestructuringImpact	$ 2		$ 1		$ 2		$ 1
Impaired Financing Receivable, Unpaid Principal Balance	3,656				3,656				3,523
Impaired Financing Receivable, Recorded Investment	3,162	[1]			3,162	[1]			3,078	[1]
Impaired Financing Receivable, Related Allowance	374				374				364
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	3,176		3,426		3,165		3,456
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	39	[2]	32	[2]	70	[2]	64	[2]
Commercial Portfolio Segment [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	126		124		107		133
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	1	[2]	1	[2]	2	[2]	1	[2]
Impaired Financing Receivable, Unpaid Principal Balance	97				97				66
Impaired Financing Receivable, Recorded Investment	80	[1]			80	[1]			48	[1]
Impaired Financing Receivable, Related Allowance	18				18				7
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	91		229		84		234
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	1	[2]	0	[2]	1	[2]	1	[2]
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	171				171				110
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	128	[1]			128	[1]			90	[1]
Commercial Portfolio Segment [Member] | Commercial and Industrial
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	70		37		63		38
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	1	[2]	0	[2]	1	[2]	0	[2]
Impaired Financing Receivable, Unpaid Principal Balance	81				81				46
Impaired Financing Receivable, Recorded Investment	70	[1]			70	[1]			38	[1]
Impaired Financing Receivable, Related Allowance	17				17				6
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	80		81		75		83
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	1	[2]	0	[2]	1	[2]	0	[2]
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	113				113				59
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	72	[1]			72	[1]			40	[1]
Commercial Portfolio Segment [Member] | Commercial Real Estate
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	9		59		8		63
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	0	[2]	1	[2]	0	[2]	1	[2]
Impaired Financing Receivable, Unpaid Principal Balance	7				7				15
Impaired Financing Receivable, Recorded Investment	3	[1]			3	[1]			7	[1]
Impaired Financing Receivable, Related Allowance	0				0				1
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	3		82		2		84
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	0	[2]	0	[2]	0	[2]	0	[2]
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	10				10				6
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	9	[1]			9	[1]			5	[1]
Commercial Portfolio Segment [Member] | Commercial Construction [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	47		28		36		32
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	0	[2]	0	[2]	1	[2]	0	[2]
Impaired Financing Receivable, Unpaid Principal Balance	9				9				5
Impaired Financing Receivable, Recorded Investment	7	[1]			7	[1]			3	[1]
Impaired Financing Receivable, Related Allowance	1				1				0
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	8		66		7		67
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	0	[2]	0	[2]	0	[2]	1	[2]
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	48				48				45
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	47	[1]			47	[1]			45	[1]
Residential Portfolio Segment [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Unpaid Principal Balance	3,285				3,285				3,266
Impaired Financing Receivable, Recorded Investment	2,851	[1]			2,851	[1]			2,859	[1]
Impaired Financing Receivable, Related Allowance	347				347				348
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	2,855		3,022		2,866		3,036
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	35	[2]	30	[2]	64	[2]	60	[2]
Residential Portfolio Segment [Member] | Residential Nonguaranteed [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Unpaid Principal Balance	2,289				2,289				2,346
Impaired Financing Receivable, Recorded Investment	1,999	[1]			1,999	[1]			2,046	[1]
Impaired Financing Receivable, Related Allowance	228				228				234
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	2,002		2,255		2,008		2,260
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	27	[2]	20	[2]	49	[2]	42	[2]
Residential Portfolio Segment [Member] | Home Equity
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Unpaid Principal Balance	724				724				661
Impaired Financing Receivable, Recorded Investment	647	[1]			647	[1]			612	[1]
Impaired Financing Receivable, Related Allowance	93				93				88
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	648		535		652		539
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	5	[2]	7	[2]	10	[2]	13	[2]
Residential Portfolio Segment [Member] | Residential Construction
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Unpaid Principal Balance	272				272				259
Impaired Financing Receivable, Recorded Investment	205	[1]			205	[1]			201	[1]
Impaired Financing Receivable, Related Allowance	26				26				26
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	205		232		206		237
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	3	[2]	3	[2]	5	[2]	5	[2]
Consumer Portfolio Segment [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Unpaid Principal Balance	103				103				81
Impaired Financing Receivable, Recorded Investment	103	[1]			103	[1]			81	[1]
Impaired Financing Receivable, Related Allowance	9				9				9
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	104		51		108		53
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	2	[2]	1	[2]	3	[2]	2	[2]
Consumer Portfolio Segment [Member] | Consumer Other Direct
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Unpaid Principal Balance	15				15				14
Impaired Financing Receivable, Recorded Investment	15	[1]			15	[1]			14	[1]
Impaired Financing Receivable, Related Allowance	2				2				2
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	15		12		15		12
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	0	[2]	0	[2]	0	[2]	0	[2]
Consumer Portfolio Segment [Member] | Consumer Indirect
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Unpaid Principal Balance	71				71				46
Impaired Financing Receivable, Recorded Investment	71	[1]			71	[1]			46	[1]
Impaired Financing Receivable, Related Allowance	3				3				2
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	72		14		74		15
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	1	[2]	1	[2]	2	[2]	1	[2]
Consumer Portfolio Segment [Member] | Consumer Credit Card
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Unpaid Principal Balance	17				17				21
Impaired Financing Receivable, Recorded Investment	17	[1]			17	[1]			21	[1]
Impaired Financing Receivable, Related Allowance	4				4				5
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	17		25		19		26
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	1	[2]	0	[2]	1	[2]	1	[2]
Impaired Financing Receivables With No Related Allowance [Member] | Commercial Portfolio Segment [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Related Allowance	0				0				0
Impaired Financing Receivables With No Related Allowance [Member] | Commercial Portfolio Segment [Member] | Commercial and Industrial
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Related Allowance	0				0				0
Impaired Financing Receivables With No Related Allowance [Member] | Commercial Portfolio Segment [Member] | Commercial Real Estate
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Related Allowance	0				0				0
Impaired Financing Receivables With No Related Allowance [Member] | Commercial Portfolio Segment [Member] | Commercial Construction [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Related Allowance	$ 0				$ 0				$ 0

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

[2] 1Of the interest income recognized during the three and six months ended June 30, 2013, cash basis interest income was $1 million and $6 million, respectively. Of the interest income recognized during the three and six months ended June 30, 2012, cash basis interest income was $4 million and $8 million, respectively.