Automotive and GM Financial Debt (Details) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Automotive [Member]
Debt Instrument [Line Items]
Long-term Debt	$ 14,662	$ 13,435
Long-term Debt, Fair Value	14,701	12,700
Finance lease liabilities	291	528
Finance lease liabilities, Fair Value	487	831
Carrying Amount	14,953	13,963
Fair Value	15,188	13,531
Automotive [Member] \| Level 1 [Member]
Debt Instrument [Line Items]
Fair Value	12,353	11,693
Automotive [Member] \| Level 2 [Member]
Debt Instrument [Line Items]
Fair Value	2,835	1,838
GM Financial [Member]
Debt Instrument [Line Items]
Carrying Amount	92,131	90,988
Fair Value	92,604	90,391
GM Financial [Member] \| Secured Debt [Member]
Debt Instrument [Line Items]
Carrying Amount	41,625	42,835
Fair Value	41,738	42,835
GM Financial [Member] \| Unsecured Debt [Member]
Debt Instrument [Line Items]
Carrying Amount	50,506	48,153
Fair Value	50,866	47,556
GM Financial [Member] \| Level 2 [Member]
Debt Instrument [Line Items]
Fair Value	90,615	88,305
GM Financial [Member] \| Level 3 [Member]
Debt Instrument [Line Items]
Fair Value	$ 1,989	$ 2,086

Finance Lease Liabilities, Fair Value Disclosure

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Sum of the carrying values as of the balance sheet date of all debt, including all short-term borrowings, long-term debt, and capital lease obligations.

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

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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.

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- Definition

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

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- 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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- 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

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