Loans - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Net Amount	$ 125,833,000,000		$ 119,296,000,000
Value of loans transferred from LHFI to LHFS	(280,000,000)		(3,695,000,000)		(754,000,000)
Transfer of Loans Held-for-sale to Portfolio Loans	43,000,000		71,000,000		63,000,000
Loans held for investment sold	807,000,000		4,800,000,000
Gain (Loss) on Sales of Loans, Net	1,000,000		(3,000,000)
Loans and Leases Receivable, Impaired, Commitment to Lend	8,000,000		1,000,000
Loans held for investment	127,877,000,000	[1]	121,470,000,000	[1]
Accrual Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Modifications, Recorded Investment	2,700,000,000		2,400,000,000
Accruing TDRs current	96.00%		95.00%
Commercial Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	64,310,000,000		58,888,000,000
Consumer Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	20,377,000,000		19,383,000,000
Residential Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	43,190,000,000		43,199,000,000
Home Equity Line of Credit [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	14,809,000,000	[2]	14,805,000,000	[2]
Federally Guaranteed Student Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage of Loan Portfolio Current	81.00%		89.00%
Loans held for investment	5,545,000,000		5,357,000,000
Residential Guaranteed [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage of Loan Portfolio Current	82.00%		83.00%
Loans held for investment	3,416,000,000		4,252,000,000
Minimum [Member] | Commercial Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans And Leases Receivable Individually Evaluated For Impairment	3,000,000
Cross-Border Outstanding Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Foreign	956,000,000		562,000,000
Credit Concentration Risk [Member] | Residential Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment	43,200,000,000		43,200,000,000
ResidentialLoansInterestOnlyHighOriginalLTVAndOrSecondLien	12,400,000,000		13,700,000,000
Residential Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan subcategory as a percent of total loans	34.00%		36.00%
Government guaranteed percent	8.00%		10.00%
Home Equity Line of Credit [Member] | Credit Concentration Risk [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unused Commitments to Extend Credit	11,200,000,000		11,700,000,000
Mortgage Loans on Real Estate [Member] | Credit Concentration Risk [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unused Commitments to Extend Credit	2,700,000,000		9,200,000,000
Residential Mortgage Interest Only Loans [Member] | Credit Concentration Risk [Member] | Residential Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
ResidentialLoansInterestOnlyHighOriginalLTVAndOrSecondLien	5,500,000,000		7,600,000,000
LoansWithNoMortgageInsuranceAndFirstLienHighOriginalLTVOrSecondLien [Member] | Residential Mortgage Interest Only Loans [Member] | Credit Concentration Risk [Member] | Residential Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
ResidentialLoansInterestOnlyHighOriginalLTVAndOrSecondLien	1,100,000,000		1,500,000,000
LoansWithNoMortgageInsuranceAndFirstLienHighOriginalLTVOrSecondLien [Member] | Residential Mortgage Amortizing Loans [Member] | Credit Concentration Risk [Member] | Residential Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
ResidentialLoansInterestOnlyHighOriginalLTVAndOrSecondLien	$ 6,900,000,000		$ 6,100,000,000

[1] 2 Includes loans of consolidated VIEs of $327 million and $365 million at December 31, 2013 and 2012, respectively.

[2] Excludes $3.4 billion and $4.3 billion at December 31, 2013 and 2012, respectively, of guaranteed residential loans. At December 31, 2013 and 2012, the majority of these loans had FICO scores of 700 and above.