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Other Expense, Net - Summary of Impairment Charges and Loss on Sale Recorded for Certain Investments (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Impairments and loss on sale of equity-accounted investments [Line Items]
Impairments and loss on sale of equity-accounted investments	$ 347	$ 700
Power & Vision [Member]
Impairments and loss on sale of equity-accounted investments [Line Items]
Impairments and loss on sale of equity-accounted investments	347	700
Tax effect on Other expense, net	(53)	(36)
Loss attributable to non-controlling interests	(75)	(127)
Non-cash impairment charge included in Net income attributable to Magna International Inc.	219	537
Power & Vision [Member] | Getrag (Jiangxi) Transmission Co., Ltd [GJT] [Member]
Impairments and loss on sale of equity-accounted investments [Line Items]
Impairment of equity-accounted investment	337	511
Power & Vision [Member] | Getrag Ford Transmission GmbH ["GFT"] [Member]
Impairments and loss on sale of equity-accounted investments [Line Items]
Impairment of equity-accounted investment		150
Power & Vision [Member] | Dongfeng Getrag Transmission Co. Ltd ["DGT"] [Member]
Impairments and loss on sale of equity-accounted investments [Line Items]
Impairments and loss on sale of equity-accounted investments	$ 10	$ 39

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- Definition

Impairment losses on equity method investments after tax attributable to parent.

+ References

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- Definition

Impairment losses on equity method investments attributable to non controlling interest.

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- Definition

Impairment of equity-accounted investment.

+ References

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- Definition

Impairments And Loss On Sale Of Equity Accounted Investments

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- Definition

Tax component of impairment losses of equity method investments.

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- Definition

This item represents the net total realized and unrealized gain (loss) included in earnings for the period as a result of selling or holding marketable securities categorized as trading, available-for-sale, or held-to-maturity, including the unrealized holding gain (loss) of held-to-maturity securities transferred to the trading security category and the cumulative unrealized gain (loss) which was included in other comprehensive income (a separate component of shareholders' equity) for available-for-sale securities transferred to trading securities during the period. Additionally, this item would include any gains (losses) realized during the period from the sale of investments accounted for under the cost method of accounting.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3602-108585

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