Summary of Significant Accounting Policies - Revenue Recognition, Share-Based Compensation and Foreign Currencies (Details) $ in Millions	12 Months Ended
	Dec. 31, 2023 USD ($) item	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Revenue Recognition
Number of performance obligations from sales of metal products | item	1
Shipping and handling costs included in operating expenses	$ 525.9	$ 509.7	$ 424.6
Share-Based Compensation
Stock-based compensation expense	65.0	65.3	70.8
Foreign Currencies
Net gain (loss) resulting from foreign currency transactions	$ (1.3)	$ (6.2)	$ (4.0)
Toll processing
Revenue Recognition
Number Of Days To Perform Services	1 day