Asset Impairment - Summary of Goodwill by Reportable Segment (Detail) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Mar. 31, 2020	Sep. 30, 2020
Goodwill [Line Items]
Goodwill, Beginning balance	$ 245	$ 245
Impairment	(230)	(230)
Foreign currency translation adjustments		(15)
United States [Member]
Goodwill [Line Items]
Goodwill, Beginning balance	125	125
Impairment		(125)
Canada [Member]
Goodwill [Line Items]
Goodwill, Beginning balance	67	67
Impairment		(60)
Foreign currency translation adjustments		(7)
International [Member]
Goodwill [Line Items]
Goodwill, Beginning balance	$ 53	53
Impairment		(45)
Foreign currency translation adjustments		$ (8)

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Amount of foreign currency translation gain (loss) which increases (decreases) an asset representing future economic benefits from other assets acquired in a business combination that are not individually identified and separately recognized.

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Amount of loss from the write-down of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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