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Segmented Information - Schedule of Aggregates External Revenues by Customer (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Revenue from External Customer [Line Items]
Sales	$ 32,647	$ 39,431
General Motors [Member]
Revenue from External Customer [Line Items]
Sales	4,921	5,732
BMW [Member]
Revenue from External Customer [Line Items]
Sales	4,714	5,469
Daimler AG [Member]
Revenue from External Customer [Line Items]
Sales	4,596	4,887
Ford Motor Company [Member]
Revenue from External Customer [Line Items]
Sales	4,004	5,270
Fiat Chrysler Automobiles [Member]
Revenue from External Customer [Line Items]
Sales	3,958	5,173
Volkswagen [Member]
Revenue from External Customer [Line Items]
Sales	3,510	4,001
Other Customers [Member]
Revenue from External Customer [Line Items]
Sales	$ 6,944	$ 8,899

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Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

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