Discontinued Operations - Schedule of Assets and Liabilities Held-for-Sale (Details) - USD ($) $ in Millions		Mar. 31, 2023	Dec. 31, 2022
Current assets:
Current assets held-for-sale	[1]	$ 108.0	$ 107.2
Current liabilities:
Current liabilities held-for-sale	[1]	37.3	43.8
Disposal Group, Held-for-sale, Not Discontinued Operations | Aluminum Products Business
Current assets:
Accounts receivable, net		32.9	24.9
Inventories, net		21.4	30.2
Other current assets		1.3	1.2
Current assets held-for-sale		55.6	56.3
Property, plant and equipment, net		47.6	46.1
Operating lease right-of-use assets		4.8	4.8
Long-term assets held-for-sale		52.4	50.9
Total assets held-for-sale		108.0	107.2
Current liabilities:
Trade accounts payable		19.4	22.8
Current portion of finance lease liabilities		2.2	2.4
Current portion of operating lease liabilities		2.1	2.3
Other accrued expenses		8.8	10.7
Current liabilities held-for-sale		32.5	38.2
Long-term finance lease liabilities		2.7	3.1
Long-term operating lease liabilities		2.1	2.5
Long-term liabilities held-for-sale		4.8	5.6
Total liabilities held-for-sale		$ 37.3	$ 43.8

[1] Our continuing operations exclude the results of our Aluminum Products business unit, which is held-for-sale as of March 31, 2023 and December 31, 2022 and presented in discontinued operations for all periods presented.