GM Financial Receivables and Transactions - Credit Risk Profile by FICO Score (Details) - GM Financial - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Financing Receivable, Credit Quality Indicator [Line Items]
GM Financial receivables, net of fees	$ 59,970	$ 53,900
Retail Finance Receivables
Financing Receivable, Credit Quality Indicator [Line Items]
2020	26,183
2019	12,050
2018	7,463
2017	3,693
2016	1,390
Prior	509
GM Financial receivables, net of fees	$ 51,288	$ 42,229
Percent	100.00%	100.00%
Retail Finance Receivables \| Prime – FICO score 680 and greater
Financing Receivable, Credit Quality Indicator [Line Items]
2020	$ 18,685
2019	7,033
2018	4,491
2017	1,917
2016	555
Prior	119
GM Financial receivables, net of fees	$ 32,800	$ 25,400
Percent	64.00%	60.10%
Retail Finance Receivables \| Near-prime – FICO score 620 to 679
Financing Receivable, Credit Quality Indicator [Line Items]
2020	$ 3,695
2019	2,097
2018	1,232
2017	603
2016	225
Prior	83
GM Financial receivables, net of fees	$ 7,935	$ 6,862
Percent	15.40%	16.30%
Retail Finance Receivables \| Sub-prime – FICO score less than 620
Financing Receivable, Credit Quality Indicator [Line Items]
2020	$ 3,803
2019	2,920
2018	1,740
2017	1,173
2016	610
Prior	307
GM Financial receivables, net of fees	$ 10,553	$ 9,967
Percent	20.60%	23.60%

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

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