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Acquisitions - Narrative (Details) - USD ($) $ in Millions				9 Months Ended
Acquisitions - Narrative (Details) - USD ($) $ in Millions	Oct. 01, 2026	Jun. 15, 2026	Jan. 05, 2026	Sep. 30, 2026
Business Combination [Line Items]
Goodwill acquired during the period				$ 34
Wilhelmshaven Plant
Business Combination [Line Items]
Business combination, consideration transferred		$ 109
Property, plant and equipment recognized		$ 90
ACI
Business Combination [Line Items]
Business combination, consideration transferred			$ 124
Preliminary purchase price accrued				$ 40
Intangible assets acquired			67
Goodwill acquired during the period			$ 38
ACI \| Minimum
Business Combination [Line Items]
Intangible assets useful life			16 years
ACI \| Maximum
Business Combination [Line Items]
Intangible assets useful life			18 years
Subsequent Event \| Rolled Steel Metal Panel Business
Business Combination [Line Items]
Business combination, consideration transferred	$ 36