Income Taxes - Provision for Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Income taxes
U.S. federal statutory tax rate (percentage)	21.00%	21.00%
U.S. federal statutory tax rate	$ 2.9	$ 6.5
Changes in valuation allowance	0.8	0.8
Other, net	(0.2)	0.6
Net controlled-foreign-corporation tested income	0.7	0.6
Incremental tax benefit on earnings or losses of subsidiary	(0.8)	(1.3)
Changes in unrecognized tax benefits	2.5
Income tax expense	6.3	8.0
Comprehensive provision for income taxes allocable to:
Income tax expense	6.3	8.0
Other comprehensive income:
Currency translation	0.5	1.9
Defined benefit pension plans	0.1	0.2
Total	6.9	10.1
Uncertain tax position, net of amounts expected to be received	2.0
Germany
Income taxes
Changes in valuation allowance	0.5
Other, net	0.4	0.8
Belgium
Income taxes
Changes in valuation allowance	0.5	0.1
Other foreign jurisdictions
Income taxes
Other, net	0.3	0.4
Kronos
Income taxes
Incremental tax benefit on investment	$ (1.3)	$ (0.5)