Revenue Recognition (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Disaggregation of Revenue [Line Items]
Net sales	$ 415.7	$ 327.3	$ 767.7	$ 600.9
Bar
Disaggregation of Revenue [Line Items]
Net sales	295.2	225.3	531.6	398.5
Tube
Disaggregation of Revenue [Line Items]
Net sales	52.8	40.9	99.3	77.0
Manufactured Components
Disaggregation of Revenue [Line Items]
Net sales	59.4	53.5	120.6	110.2
Other
Disaggregation of Revenue [Line Items]
Net sales	8.3	7.6	16.2	15.2
Mobile
Disaggregation of Revenue [Line Items]
Net sales	152.9	132.9	297.0	266.5
Industrial
Disaggregation of Revenue [Line Items]
Net sales	208.2	173.6	383.2	298.3
Energy
Disaggregation of Revenue [Line Items]
Net sales	46.3	13.2	71.3	21.0
Other
Disaggregation of Revenue [Line Items]
Net sales	$ 8.3	$ 7.6	$ 16.2	$ 15.1