Long-term Debt - Schedule of Debt (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Carrying amount
Debt Instrument [Line Items]
Less: Unamortized debt issuance costs	$ (7.6)		$ (8.1)
Total debt	337.7		334.2
Finance lease obligations	25.3		22.3
Total debt	337.7		334.2
Less: Current portion of long-term debt	14.4		13.5
Long-term debt	323.3		320.7
Interest expense	14.7	$ 18.4
Interest Paid, Capitalized, Investing Activities	11.5	19.1
Noncash interest expense, net	1.3	1.6
Financial assurance instruments
Debt Instrument [Line Items]
Interest expense	8.8	12.0
Indebtedness
Debt Instrument [Line Items]
Interest expense	2.6	2.6
Capital Lease Obligations
Debt Instrument [Line Items]
Interest expense	0.4	0.5
Amortization of debt issuance costs
Debt Instrument [Line Items]
Interest expense	1.2	1.6
Other
Debt Instrument [Line Items]
Interest expense	1.7	$ 1.7
Senior Notes | 3.250% Convertible Senior Notes due March 2028 (2028 Convertible Notes)
Debt Instrument [Line Items]
Long-term debt	$ 320.0		$ 320.0
Stated interest rate	3.25%