Business Segment Information - Reconciliation of segment income to entity income (Details) - USD ($) $ in Millions	3 Months Ended
	Aug. 31, 2024	Aug. 31, 2023
Business Segment Information
Operating income	$ 43.4	$ 25.3
Pension settlement charge		(26.7)
Losses related to sale and exit of business	(0.1)	(0.7)
Other income (expense), net	(0.1)
Interest expense	(18.8)	(5.8)
Interest income	0.5	0.4
Income (Loss) before income taxes	24.9	(7.5)
Operating segments
Business Segment Information
Operating income	57.2	33.2
Operating segments | Parts Supply
Business Segment Information
Operating income	30.1	15.1
Operating segments | Repair & Engineering
Business Segment Information
Operating income	21.1	9.1
Operating segments | Integrated Solutions
Business Segment Information
Operating income	7.7	7.7
Operating segments | Expeditionary Services
Business Segment Information
Operating income	(1.7)	1.3
Corporate and other
Business Segment Information
Operating income	$ (13.8)	$ (7.9)