Loans and Loans Held for Sale - Loans by Category (Detail) - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015	Jun. 30, 2015
Residential - prime loans:
Total loans	$ 62,098	$ 59,876	$ 58,264
Commercial Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial, financial and agricultural	33,376	31,240	29,285
Commercial real estate:
Commercial mortgage	8,582	7,959	7,874
Construction	881	1,053	1,254
Total commercial real estate loans	9,463	9,012	9,128
Commercial lease financing	3,988	4,020	4,010
Total commercial loans	46,827	44,272	42,423
Residential - prime loans:
Total loans	46,827	44,272	42,423
Consumer Loans [Member]
Commercial real estate:
Total commercial loans	15,271	15,604	15,841
Residential - prime loans:
Real estate - residential mortgage	2,285	2,242	2,252
Home equity loans	10,062	10,335	10,532
Total residential - prime loans	12,347	12,577	12,784
Consumer direct loans	1,584	1,600	1,595
Credit cards	813	806	753
Consumer indirect loans	527	621	709
Total loans	$ 15,271	$ 15,604	$ 15,841

Loans and leases receivable consumer direct loans.

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Loans and leases receivable consumer indirect loans.

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Amount before allowance of commercial leases and leveraged lease transactions where the entity is long-term creditor. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes leases covered under loss sharing agreements.

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Amount, before allowance and fees, of loans and leases receivable. Excludes loans and leases covered under loss sharing agreements.

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Amount before allowance of revolving, open-end loan, extended under a line of credit and secured by the borrower's residential property. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

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Amount before allowance of consumer mortgage. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes subordinated loans such as home equity lines of credit and loans and leases covered under loss sharing agreements.

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Amount before allowance of consumer real estate loans. Includes, but not limited to, construction financing, residential mortgage loans, and home equity lines of credit. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

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Amount before allowance of credit card loans issued to individuals. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

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Amount before allowance and after deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements.

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Amount before allowance of commercial construction loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans covered under loss sharing agreements.

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Amount before allowance of loans issued to agricultural, commercial and industrial, and financial institutions. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans covered under loss sharing agreements.

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Amount before allowance of mortgage loans on existing land or building. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans covered under loss sharing agreements.

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Amount before allowance of commercial loans issued to businesses to acquire, develop, construct, improve, or refinance land or building. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans covered under loss sharing agreements.

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