Debt and Credit Facility - Summary of Interest Expense Relating to Senior Notes and Revolving Credit Facility (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024		Dec. 31, 2023
Debt Instrument [Line Items]
Interest expense on finance lease liabilities	$ 0.8	$ 0.8		$ 0.7
Total interest expense	50.1	43.7	[1]	46.9	[1]
Senior Notes and Revolving Credit Facility
Debt Instrument [Line Items]
Interest expense on finance lease liabilities	0.8	0.8		0.7
Interest expense capitalized as construction in progress	(4.4)	(9.1)		(6.4)
Total interest expense	50.1	43.7		46.9
Revolving Credit Facility
Debt Instrument [Line Items]
Revolving Credit Facility interest expense, including commitment fees and finance cost amortization	3.0	2.4		3.0
Senior Notes
Debt Instrument [Line Items]
Senior Notes interest expense, including debt issuance cost amortization	$ 50.7	$ 49.6		$ 49.6

[1] Adjusted to reflect the retrospective change in inventory valuation methodology from LIFO to WAC. See Note 18 for further discussion.