Loan Portfolio - Loans by Category (Details) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Residential — prime loans:
Total loans	$ 90,178	$ 89,552
Commercial lease financing includes receivables held as collateral for secured borrowing	12	10
Loans	89,295	88,669
Commercial Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial and industrial	46,474	45,753
Commercial real estate:
Commercial mortgage	14,344	14,285
Construction	1,420	1,666
Total commercial real estate loans	15,764	15,951
Commercial lease financing	4,507	4,606
Total commercial/consumer loans	66,745	66,310
Residential — prime loans:
Total loans	66,745	66,310
Consumer Portfolio Segment [Member]
Commercial real estate:
Total commercial/consumer loans	23,433	23,242
Residential — prime loans:
Real estate — residential mortgage	5,615	5,513
Home equity loans	10,846	11,142
Total residential — prime loans	16,461	16,655
Consumer direct loans	2,165	1,809
Credit cards	1,086	1,144
Consumer indirect loans	3,721	3,634
Total loans	23,433	23,242
Commercial Credit Card [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial and industrial	135	132
Education Lending [Member] \| Discontinued Operations [Member]
Residential — prime loans:
Loans	$ 1,000	$ 1,100

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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Reflects the aggregate value of loans, trade receivables, securities and financial instruments that serve as collateral for obligations arising from a transfer of financial assets recorded as a secured borrowing.

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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 after allowance and 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 and loans held for sale.

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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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