Goodwill and Other Intangible Assets - Schedule of Changes in Carrying Amount of Goodwill (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Sep. 30, 2021
Goodwill [Line Items]
Goodwill	$ 415	$ 418	$ 414
Accumulated impairment losses	(93)	(28)	(28)
Goodwill [Roll Forward]
Goodwill, net - beginning balance	390	386
Goodwill, Written off Related to Sale of Business Unit		7
Translation	(3)	11
Goodwill, Total	322	390	386
Write-off of goodwill	(65)	0	0
Goodwill and Intangible Asset Impairment	65	0	0
Rolled Products
Goodwill [Line Items]
Goodwill	253	254	246
Accumulated impairment losses	0	0	0
Goodwill [Roll Forward]
Goodwill, net - beginning balance	254	246
Goodwill, Written off Related to Sale of Business Unit		1
Translation	(1)	9
Goodwill, Total	253	254	246	$ 254
Write-off of goodwill	0
Building and Construction Systems
Goodwill [Line Items]
Goodwill	97	99	97
Accumulated impairment losses	(28)	(28)	(28)
Goodwill [Roll Forward]
Goodwill, net - beginning balance	71	69
Goodwill, Written off Related to Sale of Business Unit		0
Translation	(2)	2
Goodwill, Total	69	71	69	70
Write-off of goodwill	0
Extrusions
Goodwill [Line Items]
Goodwill	65	65	71
Accumulated impairment losses	(65)	0	0
Goodwill [Roll Forward]
Goodwill, net - beginning balance	65	71
Goodwill, Written off Related to Sale of Business Unit		6
Translation	0	0
Goodwill, Total	0	$ 65	$ 71	$ 65
Write-off of goodwill	$ (65)

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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