Debt - Carrying Amount and Fair Value of Debt (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2022	Dec. 31, 2021
Automotive
Debt Instrument [Line Items]
Finance lease liabilities	$ 324	$ 349
Finance lease liabilities, Fair Value	328	362
Carrying Amount	16,893	16,818
Fair Value	18,325	20,569
Available under credit facility agreements	$ 15,188	$ 15,208
Weighted-average interest rate on outstanding short-term debt	12.10%	9.80%
Weighted-average interest rate on outstanding long-term debt	5.70%	5.80%
Net discount and debt issuance costs	$ 540	$ 512
Automotive \| Secured Debt
Debt Instrument [Line Items]
Carrying Amount	165	192
Fair Value	176	212
Automotive \| Unsecured Debt
Debt Instrument [Line Items]
Carrying Amount	16,404	16,277
Fair Value	17,821	19,995
Automotive \| Level 1
Debt Instrument [Line Items]
Fair Value	16,815	19,085
Automotive \| Level 2
Debt Instrument [Line Items]
Fair Value	1,509	1,484
GM Financial
Debt Instrument [Line Items]
Carrying Amount	92,913	92,561
Fair Value	91,649	93,758
GM Financial \| Secured Debt
Debt Instrument [Line Items]
Carrying Amount	37,362	39,338
Fair Value	37,002	39,401
GM Financial \| Unsecured Debt
Debt Instrument [Line Items]
Carrying Amount	55,552	53,223
Fair Value	$ 54,648	54,357
GM Financial \| Unsecured Debt \| Line of Credit \| $2.0 Billion Dollar Revolving Credit Facility
Debt Instrument [Line Items]
Debt term	364 days
Aggregate borrowing capacity	$ 2,000
GM Financial \| Level 2
Debt Instrument [Line Items]
Fair Value	89,810	92,250
GM Financial \| Level 3
Debt Instrument [Line Items]
Fair Value	$ 1,839	$ 1,508

Debt and Finance Lease Liabilities

No definition available.

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Namespace Prefix:	gm_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Finance Lease Liabilities, Fair Value Disclosure

+ References

No definition available.

+ Details

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Namespace Prefix:	gm_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Fair value portion of debt instrument payable, including, but not limited to, notes payable and loans payable.

+ References

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Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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Period Type:	duration

- Definition

Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

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- Definition

Amount of unamortized debt discount (premium) and debt issuance costs.

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Balance Type:	debit
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- Definition

Present value of lessee's discounted obligation for lease payments from finance lease.

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Balance Type:	credit
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- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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Balance Type:	credit
Period Type:	instant

- Definition

Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

+ References

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Weighted average interest rate of long-term debt outstanding calculated at point in time.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Weighted average interest rate of short-term debt outstanding calculated at point in time.

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- Details

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