Commitments and Contingencies - Litigation-Related Liability and Tax Administrative Matters (Details)	1 Months Ended	3 Months Ended			9 Months Ended
	Sep. 30, 2018 jurisdiction	Sep. 30, 2019 USD ($) action shares	Jun. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Sep. 30, 2019 USD ($) action employee shares	Oct. 15, 2019 USD ($)	Dec. 31, 2018 USD ($) state	Aug. 31, 2017 state
Indirect Tax Matters [Member]
Loss Contingencies [Line Items]
Estimate of possible loss		$ 900,000,000			$ 900,000,000
Ignition Switch Recall Litigations - Economic-loss cases [Member]
Loss Contingencies [Line Items]
Number of filed claims | action		100			100
Ignition Switch Recall Litigations - Economic-loss cases [Member] | Pending Litigation [Member]
Loss Contingencies [Line Items]
Number of jurisdictions | jurisdiction	27
Ignition Switch Recall Litigations - July 2009 Sale Order [Member]
Loss Contingencies [Line Items]
Number of states | state								16
Ignition Switch Recall Litigations - July 2009 Sale Order [Member] | Granted Motion to Dismiss [Member]
Loss Contingencies [Line Items]
Number of states | state								7
Ignition Switch Recall Litigations - July 2009 Sale Order [Member] | Pending Litigation [Member]
Loss Contingencies [Line Items]
Number of states | state							8	9
Ignition Switch Recall Litigations - Lost Personal Time and Certain Unjust Enrichment Claims [Member]
Loss Contingencies [Line Items]
Number of jurisdictions | jurisdiction	47
Ignition Switch Recall Litigations - Lost Personal Time and Certain Unjust Enrichment Claims [Member] | Granted Motion to Dismiss [Member]
Loss Contingencies [Line Items]
Number of jurisdictions | jurisdiction	41
Korea Wage Litigation - Hourly [Member]
Loss Contingencies [Line Items]
Number of plaintiffs | employee					10,000
Number of employees in the case | employee					5
Estimate of possible loss		$ 570,000,000			$ 570,000,000
Korea Wage Litigation - Salaried [Member]
Loss Contingencies [Line Items]
Estimate of possible loss		160,000,000			160,000,000
Korea Wage Litigation - Former Subcontract Workers [Member]
Loss Contingencies [Line Items]
Estimate of possible loss		130,000,000			130,000,000
Probable loss accrual		170,000,000			170,000,000
GM Brazil Indirect Tax Claim [Member] | Brazil [Member]
Loss Contingencies [Line Items]
Favorable settlement amount		123,000,000	$ 380,000,000	$ 857,000,000
Accrued liabilities and Other liabilities [Member]
Loss Contingencies [Line Items]
Estimated litigation liability		1,400,000,000			1,400,000,000		$ 1,300,000,000
Amended and Restated Master Sale and Purchase Agreement [Member] | Ignition Switch Recall Litigations - Contingently Issuable Shares [Member]
Loss Contingencies [Line Items]
Allowed general unsecured claims amount		$ 35,000,000,000.0			$ 35,000,000,000.0
Contingently issuable shares (in shares) | shares		30,000,000			30,000,000
Amount of allowed general unsecured claims			$ 31,900,000,000
Amended and Restated Master Sale and Purchase Agreement [Member] | Ignition Switch Recall Litigations - Contingently Issuable Shares [Member] | Subsequent Event [Member]
Loss Contingencies [Line Items]
Value of contingently issuable shares						$ 1,100,000,000