Summary of the ALLL and Related Loans and Leases Classified by Portfolio Segment (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2009	Dec. 31, 2008
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually evaluated for impairment	$ 350	[1]	$ 435	[2]
Collectively evaluated for impairment	1,767	[1]	2,416	[2]
Loans acquired with deteriorated credit quality	2	[1]	3	[2]
Unallocated	136	[1]	150	[2]
Total allowance for loan and lease losses	2,255	[3]	3,004	[3]	3,749	2,787
Individually evaluated for impairment	3,002	[4]	2,907	[5]
Collectively evaluated for impairment	77,940	[4]	74,514	[5]
Loans acquired with deteriorated credit quality	11	[4]	24	[5]
Total Loans and Leases	80,953	[6]	77,445	[5],[7]
Commercial Portfolio Segment
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually evaluated for impairment	155	[1]	209	[2]
Collectively evaluated for impairment	1,371	[1]	1,779	[2]
Loans acquired with deteriorated credit quality	1	[1]	1	[2]
Total allowance for loan and lease losses	1,527	[1]	1,989	[2]	2,517
Individually evaluated for impairment	1,170	[4]	1,076	[5]
Collectively evaluated for impairment	44,299	[4]	42,382	[5]
Loans acquired with deteriorated credit quality	3	[4]	4	[5]
Total Loans and Leases	45,472	[4]	43,462	[5]
Residential Mortgage Loans
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually evaluated for impairment	130	[1]	119	[2]
Collectively evaluated for impairment	96	[1]	189	[2]
Loans acquired with deteriorated credit quality	1	[1]	2	[2]
Total allowance for loan and lease losses	227	[1]	310	[2]	375
Individually evaluated for impairment	1,258	[4]	1,180	[5]
Collectively evaluated for impairment	9,341	[4]	7,718	[5]
Loans acquired with deteriorated credit quality	8	[4]	12	[5]
Total Loans and Leases	10,607	[4]	8,910	[5]
Consumer Portfolio Segment
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually evaluated for impairment	65	[1]	107	[2]
Collectively evaluated for impairment	300	[1]	448	[2]
Total allowance for loan and lease losses	365	[1]	555	[2]	664
Individually evaluated for impairment	574	[4]	651	[5]
Collectively evaluated for impairment	24,300	[4]	24,414	[5]
Loans acquired with deteriorated credit quality			8	[5]
Total Loans and Leases	24,874	[4]	25,073	[5]
Unallocated (Member)
Financing Receivable, Allowance for Credit Losses [Line Items]
Unallocated	136	[1]	150	[2]
Total allowance for loan and lease losses	$ 136	[1]	$ 150	[2]	$ 193

[1] Includes $14 related to leveraged leases

[2] Includes $15 related to leveraged leases.

[3] At December 31, 2011 and 2010, includes $30 and $52 of cash, $7 of other short-term investments, $50 and $29 of commercial mortgage loans, $223 and $241 of home equity loans, $259 and $648 of automobile loans, ($10) and ($14) of ALLL, $4 and $7 of other assets, $4 and $12 of other liabilities, $191 and $692 of long-term debt from consolidated VIEs that are included in their respective captions. See Note 11.

[4] Excludes $65 of residential mortgage loans measured at fair value, and includes $1,022 of leveraged leases, net of unearned income.

[5] Excludes $46 of residential mortgage loans measured at fair value, and includes $1,039 of leveraged leases, net of unearned income.

[6] Excludes $65 of loans measured at fair value.

[7] Excludes $46 of loans measured at fair value.