Variable Interest Entities (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
Mar. 31, 2021	Dec. 31, 2020
Consolidated [Abstract]
GM Financial equipment on operating leases, net	$ 37,797	$ 37,632
GM Financial
Consolidated [Abstract]
GM Financial receivables, net of fees – current	24,583	26,209
GM Financial receivables, net of fees – non-current	33,689	31,783
GM Financial short-term debt and current portion of long-term debt	33,922	35,637
GM Financial long-term debt	59,773	56,788
Consolidated VIE \| GM Financial
Consolidated [Abstract]
Restricted cash – current	2,488	2,190
Restricted cash – non-current	476	449
GM Financial receivables, net of fees – current	14,840	17,211
GM Financial receivables, net of fees – non-current	14,485	15,107
GM Financial short-term debt and current portion of long-term debt	18,228	20,450
GM Financial long-term debt	21,381	18,974
Consolidated VIE \| GM Financial \| Equipment Leased to Other Party
Consolidated [Abstract]
GM Financial equipment on operating leases, net	17,461	16,322
Variable Interest Entity, Not Primary Beneficiary
Consolidated [Abstract]
Maximum loss exposure amount	1,200	1,200
Variable Interest Entity, Not Primary Beneficiary \| Ultium Cells LLC \| Capital Addition Purchase Commitments
Consolidated [Abstract]
Committed capital contributions	$ 676	$ 776

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Amount of short-term debt and current maturity of long-term debt and capital lease obligations due within one year or the normal operating cycle, if longer.

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The minimum amount the entity agreed to spend under the long-term purchase commitment.

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Amount, after allowance for credit loss, of financing receivable, classified as current. Includes, but is not limited to, notes and loan receivable.

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Amount after accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business to produce goods and services and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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The reporting entity's maximum amount of exposure to loss as a result of its involvement with the Variable Interest Entity (VIE).

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