GM Financial Receivables and Transactions - Commercial Finance Receivables Credit Quality Indicators (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
GM Financial
Financing Receivable, Credit Quality Indicator [Line Items]
GM Financial receivables, net of fees	$ 60,107	$ 59,970
Commercial Finance Receivables \| GM Financial
Financing Receivable, Credit Quality Indicator [Line Items]
Revolving	5,702	7,662
2021	117	512
2020	479	185
2019	159	94
2018	82	100
2017	96	72
Prior	75	57
GM Financial receivables, net of fees	$ 6,710	$ 8,682
Percent	100.00%	100.00%
Commercial Finance Receivables \| GM Financial \| Group I - Performing accounts with strong to acceptable financial metrics
Financing Receivable, Credit Quality Indicator [Line Items]
Revolving	$ 5,206	$ 6,968
2021	106	510
2020	473	159
2019	134	63
2018	53	95
2017	91	43
Prior	50	19
GM Financial receivables, net of fees	$ 6,113	$ 7,857
Percent	91.10%	90.50%
Commercial Finance Receivables \| GM Financial \| Group II - Performing accounts experiencing potential weakness in financial metrics
Financing Receivable, Credit Quality Indicator [Line Items]
Revolving	$ 346	$ 491
2021	2	2
2020	2	18
2019	17	2
2018	1	3
2017	3	18
Prior	10	34
GM Financial receivables, net of fees	$ 381	$ 568
Percent	5.70%	6.50%
Commercial Finance Receivables \| GM Financial \| Group III - Non-Performing accounts with inadequate paying capacity for current obligations
Financing Receivable, Credit Quality Indicator [Line Items]
Revolving	$ 149	$ 203
2021	9	0
2020	4	8
2019	8	29
2018	28	2
2017	2	11
Prior	15	0
GM Financial receivables, net of fees	$ 215	$ 253
Percent	3.20%	2.90%
Commercial Finance Receivables \| GM Financial \| Group IV - Non-Performing accounts with inadequate paying capacity for current obligations and inherent weaknesses
Financing Receivable, Credit Quality Indicator [Line Items]
Revolving	$ 1	$ 0
2021	0	0
2020	0	0
2019	0	0
2018	0	0
2017	0	0
Prior	0	4
GM Financial receivables, net of fees	$ 1	$ 4
Percent	0.00%	0.10%
Floorplan Advances \| Commercial Finance Receivables
Financing Receivable, Credit Quality Indicator [Line Items]
Percent of revolving balance	94.00%	97.00%

Financing Receivable, Revolving, Percent of Total

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Financing Receivable, before Allowance for Credit Loss, Percent

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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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