Equity - Reconciliation of accumulated other comprehensive loss (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Increase (Decrease) in Equity [Roll Forward]
Beginning balance	$ 662.4
Total other comprehensive income (loss), net of income tax	(5.5)	$ (4.9)	$ 23.5
Ending balance	537.8	662.4
Gains (Losses) on Cash Flow Hedges
Increase (Decrease) in Equity [Roll Forward]
Beginning balance	0.0	0.0
Other comprehensive income (loss) before reclassifications	(0.4)	(1.1)
Amounts reclassified from accumulated other comprehensive income	5.8	1.1
Total other comprehensive income (loss), net of income tax	5.4
Ending balance	5.4	0.0	0.0
Pension & Postretirement
Increase (Decrease) in Equity [Roll Forward]
Beginning balance	(32.3)	(47.9)
Other comprehensive income (loss) before reclassifications	15.5	14.5
Amounts reclassified from accumulated other comprehensive income	1.5	1.1
Total other comprehensive income (loss), net of income tax	17.0	15.6
Ending balance	(15.3)	(32.3)	(47.9)
Foreign Currency Translation
Increase (Decrease) in Equity [Roll Forward]
Beginning balance	(70.1)	(49.6)
Other comprehensive income (loss) before reclassifications	(27.9)	(20.5)
Total other comprehensive income (loss), net of income tax	(27.9)	(20.5)
Ending balance	(98.0)	(70.1)	(49.6)
Accumulated Other Comprehensive Loss
Increase (Decrease) in Equity [Roll Forward]
Beginning balance	(102.4)	(97.5)
Other comprehensive income (loss) before reclassifications	(12.8)	(7.1)
Amounts reclassified from accumulated other comprehensive income	7.3	(2.2)
Total other comprehensive income (loss), net of income tax	(5.5)	(4.9)
Ending balance	$ (107.9)	$ (102.4)	$ (97.5)