Investment Agreement, Performance Agreement, Purchase Obligation Amount

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Preferred Stock, Redemption Features, Period to Call

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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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Exercise price per share or per unit of warrants or rights outstanding.

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Number of warrants or rights outstanding.

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The maximum number of common shares permitted to be issued by an entity's charter and bylaws.

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Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury.

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Number of shares of common stock outstanding. Common stock represent the ownership interest in a corporation.

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Amount of paid and unpaid common stock dividends declared with the form of settlement in cash.

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The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

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Maximum potential amount of future payments (undiscounted) the guarantor could be required to make under the guarantee or each group of similar guarantees before reduction for potential recoveries under recourse or collateralization provisions.

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The equity interest of noncontrolling shareholders, partners or other equity holders in consolidated entity.

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Minimum amount of other commitment not otherwise specified in the taxonomy. Excludes commitments explicitly modeled in the taxonomy, including but not limited to, long-term and short-term purchase commitments, recorded and unrecorded purchase obligations, supply commitments, registration payment arrangements, leases, debt, product warranties, guarantees, environmental remediation obligations, and pensions.

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The cash outflow associated with the acquisition of or advances to an entity that is related to it but not strictly controlled (for example, an unconsolidated subsidiary, affiliate, and joint venture or equity method investment) or the acquisition of an additional interest in a subsidiary (controlled entity).

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The percentage rate used to calculate dividend payments on preferred stock.

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The per share liquidation preference (or restrictions) of nonredeemable preferred stock (or preferred stock redeemable solely at the option of the issuer) that has a preference in involuntary liquidation considerably in excess of the par or stated value of the shares. The liquidation preference is the difference between the preference in liquidation and the par or stated values of the share.

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Face amount or stated value per share of preferred stock nonredeemable or redeemable solely at the option of the issuer.

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The maximum number of nonredeemable preferred shares (or preferred stock redeemable solely at the option of the issuer) permitted to be issued by an entity's charter and bylaws.

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Aggregate share number for all nonredeemable preferred stock (or preferred stock redeemable solely at the option of the issuer) held by stockholders. Does not include preferred shares that have been repurchased.

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Aggregate par or stated value of issued nonredeemable preferred stock (or preferred stock redeemable solely at the option of the issuer). This item includes treasury stock repurchased by the entity. Note: elements for number of nonredeemable preferred shares, par value and other disclosure concepts are in another section within stockholders' equity.

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The cash inflow from issuance of preferred stocks identified as being convertible into another form of financial instrument, typically the entity's common stock.

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Minimum amount of purchase arrangement in which the entity has agreed to expend funds to procure goods or services from a supplier.

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Stockholders' Equity and Noncontrolling Interests - Preferred and Common Stock (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended				3 Months Ended
	Aug. 31, 2019	May 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2027	Dec. 31, 2018	May 31, 2018
Stockholders' Equity Note [Abstract]
Preferred stock shares authorized (in shares)					2,000,000,000.0							2,000,000,000.0
Common stock shares authorized (in shares)					5,000,000,000.0							5,000,000,000.0
Preferred stock shares outstanding (in shares)					0							0
Common stock shares issued (in shares)					1,400,000,000							1,400,000,000
Common stock shares outstanding (in shares)					1,400,000,000							1,400,000,000
Warrants outstanding (in shares)												15,000,000
Exercise price of warrants (in dollars per share)												$ 18.33
Total dividends paid on common stock					$ 543	$ 540	$ 539	$ 537	$ 535	$ 536
Class of Stock [Line Items]
Guarantees - maximum liability					$ 2,700							$ 2,400
GM Cruise Holdings LLC [Member]
Class of Stock [Line Items]
Ownership percentage of external investors					17.30%
GM Cruise Holdings LLC [Member]
Class of Stock [Line Items]
Investment in subsidiaries				$ 1,100
GM Korea [Member] \| Financial Guarantee [Member]
Class of Stock [Line Items]
Guarantees - maximum liability			$ 2,800					2,800
GM Korea [Member] \| Forecast [Member]
Class of Stock [Line Items]
Planned capital expenditures											$ 2,000
Series F Preferred Stock [Member] \| GM Cruise Holdings LLC [Member]
Class of Stock [Line Items]
Proceeds from issuance of preferred stock	$ 1,200	$ 1,100
Ownership interest	6.60%
Investment in subsidiaries		$ 687
Convertible Preferred Stock [Member] \| GM Cruise Holdings LLC [Member]
Class of Stock [Line Items]
Proceeds from issuance of preferred stock				$ 900
Annual dividend rate				7.00%
The Vision Fund [Member] \| Convertible Preferred Stock [Member] \| GM Cruise Holdings LLC [Member]
Class of Stock [Line Items]
Additional purchase amount			1,350					1,350
Korea Development Bank [Member] \| Class B Preferred Shares [Member] \| GM Korea [Member]
Class of Stock [Line Items]
Proceeds from issuance of preferred stock				$ 361
Annual dividend rate				1.00%
Preferred stock purchase arrangement													$ 750
Period to call preferred shares				6 years
GM Financial [Member] \| Fixed-to-Floating Rate Cumulative Perpetual Preferred Stock, Series B [Member]
Class of Stock [Line Items]
Preferred stock issued			$ 500					$ 500
Preferred stock par value (in usd per share)			$ 0.01					$ 0.01
Preferred stock liquidation preference (in usd per share)			$ 1,000					$ 1,000
Annual dividend rate			6.50%