Goodwill (Details) - USD ($) $ in Millions	12 Months Ended
Mar. 31, 2026	Mar. 31, 2025
Goodwill [Roll Forward]
Beginning balance	$ 233.9
Ending balance	292.1	$ 233.9
Climate Solutions
Goodwill [Roll Forward]
Beginning balance	233.9	230.9
Acquisition adjustment	51.8	7.4
Effect of exchange rate changes	6.4	(4.4)
Ending balance	292.1	233.9
Proposed Performance Technologies Transaction
Goodwill [Roll Forward]
Accumulated impairment losses	40.8	40.8
L.B. White
Goodwill [Roll Forward]
Acquisitions	27.1
Climate by Design
Goodwill [Roll Forward]
Acquisitions	23.6
AbsolutAire, Inc.
Goodwill [Roll Forward]
Acquisitions	$ 1.1
Scott Springfield Manufacturing \| Climate Solutions
Goodwill [Roll Forward]
Acquisition adjustment		$ 7.4

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