Derivative Financial Instruments - Notional Amounts for Derivative Financial Instruments (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Automotive [Member] \| Not Designated as Hedges [Member]
Derivative [Line Items]
Notional	$ 6,004		$ 5,926
Automotive [Member] \| Not Designated as Hedges [Member] \| PSA Group [Member] \| Interest Income and Other Non-Operating Income, Net [Member]
Derivative [Line Items]
Gains (losses) on derivative instruments	(417)	$ 139
Automotive [Member] \| Not Designated as Hedges [Member] \| Fair Value Level 2 [Member] \| PSA Group [Member] \| Other assets [Member]
Derivative [Line Items]
Fair value of derivative instruments	546		964
Automotive [Member] \| Not Designated as Hedges [Member] \| Foreign Currency [Member] \| Fair Value Level 2 [Member]
Derivative [Line Items]
Notional	5,256		5,075
Automotive [Member] \| Not Designated as Hedges [Member] \| Commodity [Member] \| Fair Value Level 2 [Member]
Derivative [Line Items]
Notional	704		806
Automotive [Member] \| Not Designated as Hedges [Member] \| PSA Warrants [Member] \| Fair Value Level 2 [Member]
Derivative [Line Items]
Notional	44		45
GM Financial [Member]
Derivative [Line Items]
Notional	120,899		108,673
Fair Value of Assets	1,524		636
Fair Value of Liabilities	1,250		519
Collateral	668		210
Collateral available for netting	270
GM Financial [Member] \| Designated as Hedges [Member] \| Fair Value Hedges [Member] \| Interest Rate Swap [Member] \| Fair Value Level 2 [Member]
Derivative [Line Items]
Notional	8,681		9,458
Fair Value of Assets	640		234
Fair Value of Liabilities	0		23
Gains on derivative instruments, net	431
GM Financial [Member] \| Designated as Hedges [Member] \| Fair Value Hedges [Member] \| Foreign Currency Swaps [Member] \| Fair Value Level 2 [Member]
Derivative [Line Items]
Notional	1,755		1,796
Fair Value of Assets	0		22
Fair Value of Liabilities	84		71
GM Financial [Member] \| Designated as Hedges [Member] \| Cash Flow Hedges [Member] \| Interest Rate Swap [Member] \| Fair Value Level 2 [Member]
Derivative [Line Items]
Notional	1,090		590
Fair Value of Assets	0		0
Fair Value of Liabilities	21		6
GM Financial [Member] \| Designated as Hedges [Member] \| Cash Flow Hedges [Member] \| Foreign Currency Swaps [Member] \| Fair Value Level 2 [Member]
Derivative [Line Items]
Notional	5,091		4,429
Fair Value of Assets	41		40
Fair Value of Liabilities	373		119
GM Financial [Member] \| Not Designated as Hedges [Member] \| Interest Rate Contract [Member] \| Fair Value Level 2 [Member]
Derivative [Line Items]
Notional	104,282		92,400
Fair Value of Assets	843		340
Fair Value of Liabilities	$ 772		$ 300

Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and not elected to be offset.

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Fair values as of the balance sheet date of the net amount of all assets and liabilities resulting from contracts that meet the criteria of being accounted for as derivative instruments.

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Amount of right to receive cash collateral under master netting arrangements that have not been offset against derivative liabilities.

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Amount of right to receive securities collateral under master netting arrangements that have not been offset against derivative liabilities.

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Amount of realized and unrealized gain (loss) of derivative instruments not designated or qualifying as hedging instruments.

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Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities not subject to a master netting arrangement and not elected to be offset.

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Nominal or face amount used to calculate payment on derivative.

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