GM Financial Receivables and Transactions - Commercial Finance Receivables Credit Quality Indicators (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
GM Financial
Financing Receivable, Credit Quality Indicator [Line Items]
GM Financial receivables, net of fees	$ 59,970	$ 53,900
Commercial Finance Receivables \| Floorplan advances
Financing Receivable, Credit Quality Indicator [Line Items]
Percent of Contractual Amount Due	97.00%
Commercial Finance Receivables \| GM Financial
Financing Receivable, Credit Quality Indicator [Line Items]
Revolving	$ 7,662
2020	512
2019	185
2018	94
2017	100
2016	72
Prior	57
GM Financial receivables, net of fees	$ 8,682	$ 11,671
Percent	100.00%
Commercial Finance Receivables \| GM Financial \| I
Financing Receivable, Credit Quality Indicator [Line Items]
Revolving	$ 6,968
2020	510
2019	159
2018	63
2017	95
2016	43
Prior	19
GM Financial receivables, net of fees	$ 7,857
Percent	90.50%
Commercial Finance Receivables \| GM Financial \| II
Financing Receivable, Credit Quality Indicator [Line Items]
Revolving	$ 491
2020	2
2019	18
2018	2
2017	3
2016	18
Prior	34
GM Financial receivables, net of fees	$ 568
Percent	6.50%
Commercial Finance Receivables \| GM Financial \| III
Financing Receivable, Credit Quality Indicator [Line Items]
Revolving	$ 203
2020	0
2019	8
2018	29
2017	2
2016	11
Prior	0
GM Financial receivables, net of fees	$ 253
Percent	2.90%
Commercial Finance Receivables \| GM Financial \| IV
Financing Receivable, Credit Quality Indicator [Line Items]
Revolving	$ 0
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	4
GM Financial receivables, net of fees	$ 4
Percent	0.10%

Financing Receivable, Revolving, Percent of Total

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Financing Receivable, before Allowance for Credit Loss, Percent

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- Definition

Amount of financing receivable originated more than five years prior to current fiscal year.

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Amount of financing receivable originated four years prior to current fiscal year.

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Amount of financing receivable originated in current fiscal year.

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Amount of financing receivable originated in fiscal year prior to current fiscal year.

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Amount of financing receivable originated three years prior to current fiscal year.

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Amount of financing receivable originated two years prior to current fiscal year.

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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 financing receivable that can be withdrawn, repaid and redrawn.

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Amount, before allowance for credit loss, of financing receivable.

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