Securitizations and Variable Interest Entities Securitizations and Variable Interest Entities (On-balance Sheet Variable Interest Entities) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Variable Interest Entity [Line Items]
Finance receivables and loans, gross	$ 128,231	$ 129,926
Loans and Leases Receivable, Allowance	(1,263)	(1,242)	$ (1,276)
Finance receivables and loans, net	126,968	128,684
Investment in operating leases, net	8,864	8,417
Other assets	6,073	6,153
Assets	180,644	178,869	167,148
Long-term debt	34,027	44,193
Accrued expenses and other liabilities	1,972	1,676
Liabilities	166,228	165,601
On-balance sheet variable interest entities
Variable Interest Entity [Line Items]
Finance receivables and loans, gross	18,710	18,086
Loans and Leases Receivable, Allowance	(153)	(114)
Finance receivables and loans, net	18,557	17,972
Investment in operating leases, net	0	164
Other assets	787	767
Assets	19,344	18,903
Long-term debt	9,087	10,482
Accrued expenses and other liabilities	11	12
Liabilities	9,098	10,494
Consumer portfolio segment
Variable Interest Entity [Line Items]
Finance receivables and loans, gross	89,924	87,240
Consumer portfolio segment \| On-balance sheet variable interest entities
Variable Interest Entity [Line Items]
Finance receivables and loans, gross	10,791	7,282
Commercial portfolio segment
Variable Interest Entity [Line Items]
Finance receivables and loans, gross	38,307	42,686
Loans and Leases Receivable, Allowance	(133)	(141)	$ (131)
Commercial portfolio segment \| On-balance sheet variable interest entities
Variable Interest Entity [Line Items]
Finance receivables and loans, gross	$ 7,919	$ 10,804

Amount of net investment in operating leases of lessor.

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Amount of expenses incurred but not yet paid nor invoiced, and liabilities classified as other.

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Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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Sum of the carrying amounts as of the balance sheet date of all liabilities that are recognized. Liabilities are probable future sacrifices of economic benefits arising from present obligations of an entity to transfer assets or provide services to other entities in the future.

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Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

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Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. 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 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, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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