Debt - Activity (Details) - USD ($) $ in Millions	Mar. 31, 2026	Dec. 31, 2025	Jul. 22, 2025	Apr. 09, 2021
Debt Instrument [Line Items]
Total debt	$ 545.9	$ 548.3
Industrial revenue bonds
Debt Instrument [Line Items]
Hancock County industrial revenue bonds ("IRBs") due April 1, 2028, interest payable quarterly	0.0	7.8
Revolving credit facility | U.S. revolving credit facility
Debt Instrument [Line Items]
Revolving credit facility	$ 0.0	0.0
Stated interest rate, percentage	7.25%
Revolving credit facility | Foreign line of credit
Debt Instrument [Line Items]
Revolving credit facility	$ 66.1	61.0
Stated interest rate, percentage	7.18%
Senior convertible notes, 2.75% | Senior notes
Debt Instrument [Line Items]
Stated interest rate, percentage	2.75%			2.75%
Financing fees	$ 0.7
2.75% convertible senior notes due May 1, 2028, net of financing fees of $0.7 million at March 31, 2026, interest payable semiannually	$ 85.5	85.5
Senior Secured Notes, 6.875% | Senior notes
Debt Instrument [Line Items]
Stated interest rate, percentage	6.875%		6.875%
Financing fees	$ 5.8
6.875% senior secured notes due August 1, 2032, net of financing fees of $5.8 million at March 31, 2026, interest payable semiannually	$ 394.3	$ 394.0