Debt - Automotive and GM Financial Debt (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Automotive
Debt Instrument [Line Items]
Finance lease liabilities	$ 237	$ 310
Carrying Amount	17,469	14,386
Finance lease liabilities, Fair Value	256	516
Fair Value	21,576	15,928
Available under credit facility agreements(b)	$ 18,222	$ 17,285
Weighted-average interest rate on outstanding short-term debt	3.80%	4.90%
Weighted-average interest rate on outstanding long-term debt	5.60%	5.40%
Net discount and debt issuance costs	$ 540	$ 540
Automotive \| Secured Debt
Debt Instrument [Line Items]
Total debt	303	167
Fair Value	332	165
Automotive \| Unsecured Debt
Debt Instrument [Line Items]
Total debt	16,929	13,909
Fair Value	20,988	15,247
Automotive \| Level 1
Debt Instrument [Line Items]
Fair Value	19,826	13,628
Automotive \| Level 2
Debt Instrument [Line Items]
Fair Value	1,750	2,300
GM Financial
Debt Instrument [Line Items]
Total debt	92,425	88,938
Fair Value	94,948	90,399
GM Financial \| Secured Debt
Debt Instrument [Line Items]
Total debt	39,982	39,959
Fair Value	40,380	40,160
GM Financial \| Unsecured Debt
Debt Instrument [Line Items]
Total debt	52,443	48,979
Fair Value	54,568	50,239
GM Financial \| Level 2
Debt Instrument [Line Items]
Fair Value	92,922	88,481
GM Financial \| Level 3
Debt Instrument [Line Items]
Fair Value	$ 2,026	$ 1,918

Debt and Finance Lease Liabilities

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- Definition

Finance Lease Liabilities, Fair Value Disclosure

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- Definition

Amount of short-term and long-term debt and lease obligation.

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

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- Definition

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

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

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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.

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

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

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