LHFI Considered Impaired (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013		Dec. 31, 2013
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Unpaid Principal Balance	$ 3,234				$ 3,234				$ 3,625
Impaired Financing Receivable, Recorded Investment	2,868	[1]			2,868	[1]			3,159	[1]
Impaired Financing Receivable, Related Allowance	328				328				363
Impaired Financing Receivable, Interest Income, Cash Basis Method	1		1		2		6
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	3,042		3,081		3,023		3,068
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	33	[2]	34	[2]	106	[2]	102	[2]
Commercial Portfolio Segment [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	102				102				142
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	76	[1]			76	[1]			116	[1]
Impaired Financing Receivable, Unpaid Principal Balance	59				59				65
Impaired Financing Receivable, Recorded Investment	53	[1]			53	[1]			55	[1]
Impaired Financing Receivable, Related Allowance	8				8				10
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	80		90		84		65
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	0		0		1	[2]	1	[2]
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	55		42		55		30
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	0		0		1	[2]	1	[2]
Residential Portfolio Segment [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	717				717				740
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	459	[1]			459	[1]			442	[1]
Impaired Financing Receivable, Unpaid Principal Balance	2,233				2,233				2,568
Impaired Financing Receivable, Recorded Investment	2,157	[1]			2,157	[1]			2,436	[1]
Impaired Financing Receivable, Related Allowance	313				313				345
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	468		438		482		456
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	5	[2]	4	[2]	14	[2]	13	[2]
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	2,299		2,397		2,267		2,397
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	27	[2]	29	[2]	85	[2]	83	[2]
Consumer Portfolio Segment [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Unpaid Principal Balance	123				123				110
Impaired Financing Receivable, Recorded Investment	123	[1]			123	[1]			110	[1]
Impaired Financing Receivable, Related Allowance	7				7				8
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	140		114		135		120
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	1	[2]	1	[2]	5	[2]	4	[2]
Commercial and Industrial [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	84				84				81
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	62	[1]			62	[1]			56	[1]
Impaired Financing Receivable, Unpaid Principal Balance	48				48				51
Impaired Financing Receivable, Recorded Investment	43	[1]			43	[1]			49	[1]
Impaired Financing Receivable, Related Allowance	7				7				10
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	65		84		68		58
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	0		0		1	[2]	1	[2]
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	45		35		46		25
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	0		0		1	[2]	1	[2]
Commercial Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	18				18				61
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	14	[1]			14	[1]			60	[1]
Impaired Financing Receivable, Unpaid Principal Balance	11				11				8
Impaired Financing Receivable, Recorded Investment	10	[1]			10	[1]			3	[1]
Impaired Financing Receivable, Related Allowance	1				1				0
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	15		5		16		6
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	0		0		0		0
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	10		3		9		3
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	0		0		0		0
Commercial Construction [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Unpaid Principal Balance	0				0				6
Impaired Financing Receivable, Recorded Investment	0				0				3	[1]
Impaired Financing Receivable, Related Allowance	0				0				0
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	0		1		0		1
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	0		0		0		0
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	0		4		0		2
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	0		0		0		0
Residential Nonguaranteed [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	676				676				672
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	447	[1]			447	[1]			425	[1]
Impaired Financing Receivable, Unpaid Principal Balance	1,381				1,381				1,685
Impaired Financing Receivable, Recorded Investment	1,378	[1]			1,378	[1]			1,626	[1]
Impaired Financing Receivable, Related Allowance	223				223				226
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	454		420		467		434
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	5	[2]	4	[2]	14	[2]	13	[2]
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	1,467		1,582		1,443		1,579
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	18	[2]	19	[2]	59	[2]	58	[2]
Home Equity Line of Credit [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Unpaid Principal Balance	702				702				710
Impaired Financing Receivable, Recorded Investment	629	[1]			629	[1]			638	[1]
Impaired Financing Receivable, Related Allowance	70				70				96
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	668		634		662		640
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	7	[2]	7	[2]	20	[2]	17	[2]
Residential Construction [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	41				41				68
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	12	[1]			12	[1]			17	[1]
Impaired Financing Receivable, Unpaid Principal Balance	150				150				173
Impaired Financing Receivable, Recorded Investment	150	[1]			150	[1]			172	[1]
Impaired Financing Receivable, Related Allowance	20				20				23
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	14		18		15		22
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	0	[2]	0	[2]	0	[2]	0	[2]
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	164		181		162		178
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	2	[2]	3	[2]	6	[2]	8	[2]
Consumer Other Direct [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Unpaid Principal Balance	13				13				14
Impaired Financing Receivable, Recorded Investment	13	[1]			13	[1]			14	[1]
Impaired Financing Receivable, Related Allowance	0				0				0
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	14		15		14		16
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	0		0		0		0
Consumer Indirect [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Unpaid Principal Balance	100				100				83
Impaired Financing Receivable, Recorded Investment	100	[1]			100	[1]			83	[1]
Impaired Financing Receivable, Related Allowance	5				5				5
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	116		84		110		87
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	1	[2]	1	[2]	4	[2]	3	[2]
Consumer Credit Card Financing Receivable [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Unpaid Principal Balance	10				10				13
Impaired Financing Receivable, Recorded Investment	10	[1]			10	[1]			13	[1]
Impaired Financing Receivable, Related Allowance	2				2				3
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	10		15		11		17
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	0		0		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] | Residential 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 and Industrial [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Related Allowance	0				0				0
Impaired Financing Receivables With No Related Allowance [Member] | Commercial Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Related Allowance	0				0				0
Impaired Financing Receivables With No Related Allowance [Member] | Residential Nonguaranteed [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Related Allowance	0				0				0
Impaired Financing Receivables With No Related Allowance [Member] | Residential 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] Of the interest income recognized during the three and nine months ended September 30, 2014, cash basis interest income was less than $1 million and $2 million, respectively.Of the interest income recognized during the three and nine months ended September 30, 2013, cash basis interest income was $1 million and $6 million, respectively.