v3.23.1

Segment and Related Information​ - Operating Results (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total sales	$ 1,929	$ 2,191
Provision for depreciation and amortization	53	60
Rolled Products | Disposed of by sale | Samara Manufacturing Site
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Segment Adjusted EBITDA		18
Intersegment sales
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total sales	11	13
Intersegment sales | Rolled Products
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total sales	11	12
Intersegment sales | Building and Construction Systems
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total sales	0	0
Intersegment sales | Extrusions
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total sales	0	1
Operating segments
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total sales	1,943	2,205
Segment Adjusted EBITDA	167	215
Provision for depreciation and amortization	49	56
Operating segments | Rolled Products
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total sales	1,515	1,816
Segment Adjusted EBITDA	117	176
Provision for depreciation and amortization	42	48
Operating segments | Rolled Products | Disposed of by sale | Samara Manufacturing Site
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Segment Adjusted EBITDA		18
Operating segments | Building and Construction Systems
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total sales	308	291
Segment Adjusted EBITDA	54	44
Provision for depreciation and amortization	4	4
Operating segments | Extrusions
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total sales	120	98
Segment Adjusted EBITDA	4	5
Provision for depreciation and amortization	3	4
External Sales Including Reconciling Items
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total sales	1,932	2,192
External Sales Including Reconciling Items | Rolled Products
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total sales	1,504	1,804
External Sales Including Reconciling Items | Rolled Products | Disposed of by sale | Samara Manufacturing Site
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total sales		233
External Sales Including Reconciling Items | Building and Construction Systems
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total sales	308	291
External Sales Including Reconciling Items | Extrusions
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total sales	$ 120	$ 97

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