LHFI by Credit Quality Indicator (Detail) (USD $) In Millions, unless otherwise specified	Jun. 30, 2012		Dec. 31, 2011
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	$ 124,560	[1]	$ 122,495	[1]
Commercial and Industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	52,030		49,538
Commercial and Industrial | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	50,130		47,683
Commercial and Industrial | Criticized Accruing
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	1,569		1,507
Commercial and Industrial | Criticized Nonaccruing
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	331		348
Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	4,825		5,094
Commercial Real Estate | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	3,836		3,845
Commercial Real Estate | Criticized Accruing
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	756		961
Commercial Real Estate | Criticized Nonaccruing
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	233		288
Commercial Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	959		1,240
Commercial Construction [Member] | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	581		581
Commercial Construction [Member] | Criticized Accruing
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	247		369
Commercial Construction [Member] | Criticized Nonaccruing
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	131		290
Residential Nonguaranteed [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	24,405	[2]	23,243	[2]
Residential Nonguaranteed [Member] | FICO Score 700 and Above
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	17,567	[2]	16,139	[2]
Residential Nonguaranteed [Member] | FICO Score Between 620 and 699
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	4,149	[2]	4,132	[2]
Residential Nonguaranteed [Member] | FICO Score Below 620
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	2,689	[2],[3]	2,972	[2],[3]
Home Equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	15,281		15,765
Home Equity | FICO Score 700 and Above
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	11,583		11,084
Home Equity | FICO Score Between 620 and 699
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	2,405		2,903
Home Equity | FICO Score Below 620
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	1,293	[3]	1,778	[3]
Residential Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	853		980
Residential Construction | FICO Score 700 and Above
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	613		661
Residential Construction | FICO Score Between 620 and 699
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	158		202
Residential Construction | FICO Score Below 620
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	82	[3]	117	[3]
Consumer Other Direct
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	2,225		2,059
Consumer Other Direct | FICO Score 700 and Above
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	1,829		1,614
Consumer Other Direct | FICO Score Between 620 and 699
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	325		359
Consumer Other Direct | FICO Score Below 620
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	71	[3]	86	[3]
Consumer Indirect
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	10,506		10,165
Consumer Indirect | FICO Score 700 and Above
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	7,965		7,397
Consumer Indirect | FICO Score Between 620 and 699
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	1,886		1,990
Consumer Indirect | FICO Score Below 620
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	655	[3]	778	[3]
Consumer Credit Card
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	565		540
Consumer Credit Card | FICO Score 700 and Above
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	379		347
Consumer Credit Card | FICO Score Between 620 and 699
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	142		142
Consumer Credit Card | FICO Score Below 620
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	$ 44	[3]	$ 51	[3]

[1] Includes loans of consolidated VIEs390 3,322

[2] Excludes $5.7 billion and $6.7 billion at June 30, 2012 and December 31, 2011, respectively, of guaranteed residential loans. At both June 30, 2012 and December 31, 2011, the majority of these loans had FICO scores of 700 and above.

[3] For substantially all loans with refreshed FICO scores below 620, the borrower’s FICO score at the time of origination exceeded 620 but has since deteriorated as the loan has seasoned.