Summary of the ALLL and Related Loans and Leases Classified by Portfolio Segment (Parenthetical) (Detail) (USD $) In Millions, unless otherwise specified	Jun. 30, 2013		Mar. 31, 2013	Dec. 31, 2012		Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011
Financing Receivable, Allowance for Credit Losses
Allowance for loan and lease losses	$ 1,735	[1]	$ 1,783	$ 1,854	[1]	$ 2,016	$ 2,126	$ 2,255
Portfolio loans and leases	86,949	[2],[3],[4]		85,706	[5],[6]
Number of Contracts	6,181	[7]				8,128
Recorded Investment	2,728	[8]		2,823	[9]
Leveraged Leases
Financing Receivable, Allowance for Credit Losses
Allowance for loan and lease losses	10			11
Portfolio loans and leases	872			862
Residential Mortgage Loans
Financing Receivable, Allowance for Credit Losses
Portfolio loans and leases at fair value	83			76
Variable Interest Entity, Primary Beneficiary
Financing Receivable, Allowance for Credit Losses
Allowance for loan and lease losses	11
Number of Contracts	5
Recorded Investment	$ 29

[1] Includes $50 and $50 of commercial mortgage loans, $(13) and $(5) of ALLL, and $1 and $3 of other assets from consolidated VIEs that are included in their respective captions above at June 30, 2013 and December 31, 2012, respectively. See Note 8.

[2] Excludes $83 of residential mortgage loans measured at fair value, and includes $872 of leveraged leases, net of unearned income.

[3] Excludes $83 of loans measured at fair value.

[4] Includes an immaterial amount of government insured commercial loans 30-89 days and 90 days past due and accruing whose repayments are insured by the SBA at June 30, 2013.

[5] Excludes $76 of loans measured at fair value.

[6] Includes an immaterial amount of government insured commercial loans 30-89 and 90 days past due and accruing whose repayments are insured by the SBA at December 31, 2012.

[7] Excludes all loans and leases held for sale and loans acquired with deteriorated credit quality

[8] Includes $475, $1,201 and $470, respectively, of commercial, residential mortgage and consumer TDRs on accrual status; $196, $105 and $57, respectively, of commercial, residential mortgage and consumer TDRs on nonaccrual status.

[9] Includes $431, $1,175 and $480, respectively, of commercial, residential mortgage and consumer TDRs on accrual status;$177, $123 and $64, respectively, of commercial, residential mortgage and consumer TDRs on nonaccrual status.