Related Party Transactions - Related Party Payables (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Commercial Finance Receivables [Member]
Related Party Transaction [Line Items]
Finance receivables, net	$ 12,071	$ 12,654
Retail Finance Receivables [Member]
Related Party Transaction [Line Items]
Finance receivables, net	41,402	39,858
Affiliated Entity [Member]
Related Party Transaction [Line Items]
Subvention receivable	676	727
Leased vehicle subvention earned	3,273	3,274	$ 3,046
Affiliated Entity [Member] \| Commercial Finance Receivables [Member]
Related Party Transaction [Line Items]
Finance receivables, net	478	445
Commercial loan funding payable	74	61
Interest subvention earned	61	67	54
Affiliated Entity [Member] \| Retail Finance Receivables [Member]
Related Party Transaction [Line Items]
Finance receivables, net	39	134
Interest subvention earned	527	487	438
GM [Member]
Related Party Transaction [Line Items]
Revenue from related parties	$ 4,100	$ 3,800	$ 4,300

Related Party, Leased Vehicle Income Earned

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Amount of interest income earned from interest-bearing assets owed to the entity by related party.

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The amount for notes payable (written promise to pay), due to related parties.

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Amount, after allowance for credit loss, of financing receivable. Excludes financing receivable covered under loss sharing agreement.

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For an unclassified balance sheet, amounts due from parties associated with the reporting entity as evidenced by a written promise to pay.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount of revenue, fees and commissions earned from transactions between (a) a parent company and its subsidiaries; (b) subsidiaries of a common parent; (c) an entity and trusts for the benefit of employees, for example, but not limited to, pension and profit-sharing trusts that are managed by or under the trusteeship of the entity's management; (d) an entity and its principal, owners, management, or members of their immediate families; and (e) affiliates.

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