Financial Instruments and Risk Management - Effect of Cash Flow Hedge Accounting on AOCI (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2026	Sep. 30, 2025	Sep. 30, 2026	Sep. 30, 2025
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Amount of Gain (Loss) Recognized in AOCI	$ (0.5)	$ (0.9)	$ (0.1)	$ (2.6)
Amount of Gain (Loss) Reclassified from AOCI into Net income (loss)	(0.3)	0.2	(0.4)	(0.1)
Currency exchange contracts \| Income Statement Location [Axis]: us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Amount of Gain (Loss) Recognized in AOCI	0.1	0.1	0.1	(0.4)
Amount of Gain (Loss) Reclassified from AOCI into Net income (loss)	0.0	(0.1)	0.0	(0.3)
Natural gas contracts \| Income Statement Location [Axis]: us-gaap:CostOfGoodsAndServicesSold
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Amount of Gain (Loss) Recognized in AOCI	(0.6)	(0.8)	(0.6)	(1.2)
Amount of Gain (Loss) Reclassified from AOCI into Net income (loss)	(0.3)	0.3	(0.4)	0.2
Interest rate swap contracts \| Income Statement Location [Axis]: us-gaap:InterestIncomeExpenseNonoperatingNet
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Amount of Gain (Loss) Recognized in AOCI	0.0	(0.2)	0.4	(1.0)
Amount of Gain (Loss) Reclassified from AOCI into Net income (loss)	$ 0.0	$ 0.0	$ 0.0	$ 0.0