GM Financial Receivables and Transactions - Credit Risk Profile by FICO Score (Details) - GM Financial - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 2020
Financing Receivable, Credit Quality Indicator [Line Items]
GM Financial receivables, net of fees	$ 60,107	$ 59,970
Retail Finance Receivables
Financing Receivable, Credit Quality Indicator [Line Items]
2021	7,948	26,183
2020	23,897	12,050
2019	10,652	7,463
2018	6,420	3,693
2017	3,068	1,390
Prior	1,412	509
GM Financial receivables, net of fees	$ 53,397	$ 51,288	$ 42,474
Percent	100.00%	100.00%
Retail Finance Receivables \| Prime – FICO score 680 and greater
Financing Receivable, Credit Quality Indicator [Line Items]
2021	$ 5,554	$ 18,685
2020	17,004	7,033
2019	6,171	4,491
2018	3,841	1,917
2017	1,565	555
Prior	478	119
GM Financial receivables, net of fees	$ 34,613	$ 32,800
Percent	64.80%	64.00%
Retail Finance Receivables \| Near-prime – FICO score 620 to 679
Financing Receivable, Credit Quality Indicator [Line Items]
2021	$ 1,167	$ 3,695
2020	3,377	2,097
2019	1,870	1,232
2018	1,062	603
2017	509	225
Prior	231	83
GM Financial receivables, net of fees	$ 8,216	$ 7,935
Percent	15.40%	15.40%
Retail Finance Receivables \| Sub-prime – FICO score less than 620
Financing Receivable, Credit Quality Indicator [Line Items]
2021	$ 1,227	$ 3,803
2020	3,516	2,920
2019	2,611	1,740
2018	1,517	1,173
2017	994	610
Prior	703	307
GM Financial receivables, net of fees	$ 10,568	$ 10,553
Percent	19.80%	20.60%

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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