v3.22.1

Segment and Related Information​ - Operating Results (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Segment Adjusted EBITDA	$ 215	$ 189
Provision for depreciation and amortization	60	63
Intersegment sales
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total sales	13	7
Intersegment sales | Rolled Products
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total sales	12	7
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	1	0
Operating segments
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total sales	2,205	1,682
Segment Adjusted EBITDA	215	189
Provision for depreciation and amortization	56	58
Operating segments | Rolled Products
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total sales	1,816	1,371
Segment Adjusted EBITDA	176	165
Provision for depreciation and amortization	48	48
Operating segments | Building and Construction Systems
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total sales	291	236
Segment Adjusted EBITDA	44	28
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	98	75
Segment Adjusted EBITDA	5	4
Provision for depreciation and amortization	4	6
Third-party sales
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total sales	2,191	1,675
Third-party sales | External Sales Including Reconciling Items
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total sales	2,192	1,675
Third-party sales | External Sales Including Reconciling Items | Rolled Products
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total sales	1,804	1,364
Third-party sales | 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	291	236
Third-party sales | External Sales Including Reconciling Items | Extrusions
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total sales	$ 97	$ 75

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