Business Segment Information - Reconciliation of segment income to entity income (Details) - USD ($) $ in Millions	12 Months Ended
	May 31, 2025	May 31, 2024	May 31, 2023
Business Segment Information
Operating income	$ 185.2	$ 129.2	$ 133.9
Pension settlement charge		(26.7)
Losses related to sale and exit of business	(72.4)	(2.8)	(0.7)
Other income (expense), net	(0.3)	(0.4)	(0.8)
Interest expense	(75.4)	(43.2)	(12.2)
Interest income	1.8	2.2	1.0
Income from continuing operations before income taxes	38.9	58.3	121.2
Parts Supply
Business Segment Information
Operating income	156.8	109.8	93.7
Repair & Engineering
Business Segment Information
Operating income	81.2	52.5	35.3
Integrated Solutions
Business Segment Information
Operating income	36.4	23.9	30.5
Expeditionary Services
Business Segment Information
Operating income	10.1	3.5	7.7
Corporate and other
Business Segment Information
Operating income	(99.3)	(60.5)	(33.3)
Operating segments
Business Segment Information
Operating income	284.5	189.7	167.2
Operating segments | Parts Supply
Business Segment Information
Operating income	156.8	109.8	93.7
Operating segments | Repair & Engineering
Business Segment Information
Operating income	81.2	52.5	35.3
Operating segments | Integrated Solutions
Business Segment Information
Operating income	36.4	23.9	30.5
Operating segments | Expeditionary Services
Business Segment Information
Operating income	$ 10.1	$ 3.5	$ 7.7