Maximum percent of total long-lived assets from any inidividual country outside the United States.

No definition available.

Name:	gm_Maximumpercentoftotallonglivedassets
Namespace Prefix:	gm_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Maximum percent of total net sales and revenues from any inidividual country outside the United States.

+ References

No definition available.

+ Details

Name:	gm_Maximumpercentoftotalnetsalesandrevenues
Namespace Prefix:	gm_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The aggregate financial services revenue and operating interest income earned during the reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.1(d))
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

+ Details

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

- Definition

Long-lived assets other than financial instruments, long-term customer relationships of a financial institution, mortgage and other servicing rights, deferred policy acquisition costs, and deferred tax assets.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 41
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=68060357&loc=d3e9038-108599

+ Details

Name:	us-gaap_NoncurrentAssets
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.1)
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

+ Details

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

- 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

Name:	us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Total revenue from sale of goods and services rendered during the reporting period, in the normal course of business, reduced by sales returns and allowances, and sales discounts.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.1)
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

+ Details

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

- Details

Name:	us-gaap_StatementGeographicalAxis=country_US
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementGeographicalAxis=us-gaap_NonUsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	gm_BusinessGroupAxis=gm_AutomotiveMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	gm_BusinessGroupAxis=gm_GmFinancialMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Segment Reporting Revenues and long-lived assets by geographic region (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales and revenue									$ 156,849	$ 145,922	$ 151,092
GM Financial revenue									9,531	6,434	4,837
Total net sales and revenue	$ 43,918	$ 42,825	$ 42,372	$ 37,265	$ 39,621	$ 38,843	$ 38,180	$ 35,712	166,380	152,356	155,929
Long-Lived Assets	$ 72,242				$ 54,224				72,242	54,224	38,400
U.S.
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales and revenue									110,848	100,008	93,559
GM Financial revenue									7,462	4,357	2,549
Non-U.S.
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales and revenue									46,001	45,914	57,533
GM Financial revenue									$ 2,069	$ 2,077	$ 2,288
Maximum percent of total net sales and revenue in an individual country									10.00%	10.00%	10.00%
Maximum percent of total long-lived assets in an individual country	10.00%				10.00%				10.00%	10.00%	10.00%
Automotive [Member] \| U.S.
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-Lived Assets	$ 22,241				$ 21,091				$ 22,241	$ 21,091	$ 18,813
Automotive [Member] \| Non-U.S.
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-Lived Assets	15,196				12,742				15,196	12,742	12,355
GM Financial [Member] \| U.S.
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-Lived Assets	32,506				18,501				32,506	18,501	5,477
GM Financial [Member] \| Non-U.S.
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-Lived Assets	$ 2,299				$ 1,890				$ 2,299	$ 1,890	$ 1,755