Line of Credit Facility, Covenant Terms, Dividend Restrictions, Amount Outstanding

No definition available.

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

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=119993939&loc=d3e28551-108399

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400

+ Details

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

+ Details

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Data Type:	xbrli:stringItemType
Balance Type:	na
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.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Weighted average interest rate of debt outstanding.

+ References

No definition available.

+ Details

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

- 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.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19(b),22(b))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ 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:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The cash inflow from a contractual arrangement with the lender, including letter of credit, standby letter of credit and revolving credit arrangements, under which borrowings can be made up to a specific amount at any point in time with maturities due beyond one year or the operating cycle, if longer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3255-108585

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The cash outflow for the settlement of obligation drawn from a contractual arrangement with the lender, including letter of credit, standby letter of credit and revolving credit arrangements, under which borrowings can be made up to a specific amount at any point in time with maturities due beyond one year or the operating cycle, if longer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3291-108585

+ Details

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

- Definition

The cash outflow for a long-term debt where the holder has highest claim on the entity's asset in case of bankruptcy or liquidation during the period.

+ References

+ Details

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Namespace Prefix:	us-gaap_
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Balance Type:	credit
Period Type:	duration

- Details

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- Details

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Balance Type:
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- Details

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Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=gm_FiveYearRevolvingCreditFacilityDue2023Member
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Balance Type:
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- Details

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- Details

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- Details

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- Details

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- Details

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Data Type:	na
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- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_RevolvingCreditFacilityMember
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Data Type:	na
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- Details

Name:	us-gaap_DebtInstrumentAxis=gm_TwoBillionDollarRevolvingCreditFacilityMember
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- Details

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- Details

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Debt - Narrative (Details) - USD ($)	1 Months Ended						9 Months Ended
Debt - Narrative (Details) - USD ($)	Oct. 31, 2020	Sep. 30, 2020	Aug. 31, 2020	May 31, 2020	Apr. 30, 2020	Mar. 31, 2020	Sep. 30, 2020
Unsecured Debt [Member] \| Line of Credit [Member]
Debt Instrument [Line Items]
Proceeds borrowed						$ 2,000,000,000.0
Debt term				3 years	3 years
Aggregate borrowing capacity				$ 2,000,000,000.0	$ 3,000,000,000.0
Repayments of lines of credit		$ 2,000,000,000.0
Dividend restriction covenant, amount outstanding		5,000,000,000.0					$ 5,000,000,000.0
Unsecured Debt [Member] \| Line of Credit [Member] \| Three Year Revolving Credit Facility April 2022 [Member]
Debt Instrument [Line Items]
Aggregate borrowing capacity					$ 3,600,000,000
Unsecured Debt [Member] \| Line of Credit [Member] \| Five Year Revolving Credit Facility Due 2023 [Member]
Debt Instrument [Line Items]
Proceeds borrowed						10,500,000,000
Debt term							5 years
Aggregate borrowing capacity		$ 10,500,000,000					$ 10,500,000,000
Unsecured Debt [Member] \| Line of Credit [Member] \| Five Year Revolving Credit Facility Due 2023 [Member] \| Subsequent Event [Member]
Debt Instrument [Line Items]
Debt term	5 years
Aggregate borrowing capacity	$ 10,500,000,000
Repayments of lines of credit	$ 3,900,000,000
Unsecured Debt [Member] \| Line of Credit [Member] \| Three Year Revolving Credit Facility April 2021 [Member]
Debt Instrument [Line Items]
Proceeds borrowed						$ 3,400,000,000
Debt term		3 years			3 years		3 years
Aggregate borrowing capacity		$ 4,000,000,000.0			$ 4,000,000,000.0		$ 4,000,000,000.0
Repayments of lines of credit		3,200,000,000
Unsecured Debt [Member] \| Senior Notes [Member]
Debt Instrument [Line Items]
Principal amount				$ 4,000,000,000.0
Weighted average interest rate (percent)				6.11%
Unsecured Debt [Member] \| Senior Notes [Member] \| Floating Rate Notes [Member]
Debt Instrument [Line Items]
Repayments of debt			$ 500,000,000
GM Financial [Member] \| Line of Credit [Member]
Debt Instrument [Line Items]
Aggregate borrowing capacity		$ 17,300,000,000					$ 17,300,000,000
GM Financial [Member] \| Unsecured Debt [Member] \| Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Weighted average interest rate (percent)		2.46%					2.46%
GM Financial [Member] \| Unsecured Debt [Member] \| Line of Credit [Member] \| $2.0 Billion Dollar Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Debt term				364 days	364 days		364 days
Aggregate borrowing capacity		$ 2,000,000,000.0		$ 2,000,000,000.0	$ 2,000,000,000.0		$ 2,000,000,000.0
GM Financial [Member] \| Unsecured Debt [Member] \| Senior Notes [Member]
Debt Instrument [Line Items]
Principal amount		$ 8,400,000,000					$ 8,400,000,000
Weighted average interest rate (percent)		3.08%					3.08%
Weighted-average interest rate on outstanding long-term debt		3.27%					3.27%
GM Financial [Member] \| Secured Debt [Member] \| Notes Payable, Other Payables [Member] \| Securitization notes payable [Member]
Debt Instrument [Line Items]
Principal amount		$ 16,600,000,000					$ 16,600,000,000
Weighted average interest rate (percent)		1.33%					1.33%
Weighted-average interest rate on outstanding long-term debt		2.22%					2.22%
Maximum [Member] \| GM Financial [Member] \| Unsecured Debt [Member] \| Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Debt term							4 years