Discontinued Operations - Assets and liabilities (Details) - USD ($) $ in Millions	Sep. 29, 2024	Dec. 31, 2023
Held-for-sale assets
Current assets	$ 22.1	$ 8.9
Held-for-sale liabilities
Held-for-sale liabilities	7.2	3.9
Discontinued operations | Superform Aluminum Superplastic
Held-for-sale assets
Inventory	4.1	3.3
Accounts and other receivables	2.1	2.3
Current assets	6.2	5.6
Right-of-use-assets	1.6	2.1
Held-for-sale assets	7.8	7.7
Held-for-sale liabilities
Accounts payable	0.7	0.9
Accrued liabilities	0.4	0.4
Other liabilities	2.2	2.6
Held-for-sale liabilities	$ 3.3	$ 3.9