Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Changes in Accumulated Other Comprehensive Loss [Abstract]
Beginning balance			$ 910.2
Ending balance	$ 1,053.5		1,053.5
Accumulated other comprehensive loss
Changes in Accumulated Other Comprehensive Loss [Abstract]
Beginning balance	(131.9)	$ (169.5)	(181.3)	$ (163.4)
Other comprehensive income (loss) before reclassifications	(7.2)	21.1	41.4	14.2
Income taxes	0.0	(0.3)	(0.8)	(0.6)
Total other comprehensive income (loss)	(5.8)	21.7	43.6	15.6
Ending balance	(137.7)	(147.8)	(137.7)	(147.8)
Foreign Currency Translation
Changes in Accumulated Other Comprehensive Loss [Abstract]
Beginning balance	(29.6)	(69.7)	(76.8)	(62.8)
Other comprehensive income (loss) before reclassifications	(5.9)	20.7	41.3	13.8
Income taxes	0.0	0.0	0.0	0.0
Total other comprehensive income (loss)	(5.9)	20.7	41.3	13.8
Ending balance	(35.5)	(49.0)	(35.5)	(49.0)
Defined Benefit Plans
Changes in Accumulated Other Comprehensive Loss [Abstract]
Beginning balance	(103.0)	(99.9)	(103.8)	(100.7)
Other comprehensive income (loss) before reclassifications	0.0	0.0	0.0	0.0
Reclassification from accumulated other comprehensive income (loss)	1.1	1.0	2.2	2.1
Income taxes	(0.3)	(0.2)	(0.6)	(0.5)
Total other comprehensive income (loss)	0.8	0.8	1.6	1.6
Ending balance	(102.2)	(99.1)	(102.2)	(99.1)
Cash Flow Hedges
Changes in Accumulated Other Comprehensive Loss [Abstract]
Beginning balance	0.7	0.1	(0.7)	0.1
Other comprehensive income (loss) before reclassifications	(1.3)	0.4	0.1	0.4
Reclassification from accumulated other comprehensive income (loss)	0.3	(0.1)	0.8	(0.1)
Income taxes	0.3	(0.1)	(0.2)	(0.1)
Total other comprehensive income (loss)	$ (0.7)	0.2	$ 0.7	0.2
Ending balance		$ 0.3		$ 0.3