Business Segment Information - Sales by Segment (Details) - USD ($) $ in Millions	3 Months Ended
	Aug. 31, 2024	Aug. 31, 2023
Business Segment Information
Net sales	$ 661.7	$ 549.7
Inter-segment Sales
Business Segment Information
Net sales	25.4	21.4
Total Sales
Business Segment Information
Net sales	687.1	571.1
Parts Supply
Business Segment Information
Net sales	249.7	236.8
Parts Supply | Inter-segment Sales
Business Segment Information
Net sales	2.5	0.8
Parts Supply | Total Sales
Business Segment Information
Net sales	252.2	237.6
Repair & Engineering
Business Segment Information
Net sales	217.6	137.5
Repair & Engineering | Inter-segment Sales
Business Segment Information
Net sales	22.6	19.5
Repair & Engineering | Total Sales
Business Segment Information
Net sales	240.2	157.0
Integrated Solutions
Business Segment Information
Net sales	168.9	156.3
Integrated Solutions | Inter-segment Sales
Business Segment Information
Net sales	0.3	1.1
Integrated Solutions | Total Sales
Business Segment Information
Net sales	169.2	157.4
Expeditionary Services
Business Segment Information
Net sales	25.5	19.1
Expeditionary Services | Total Sales
Business Segment Information
Net sales	$ 25.5	$ 19.1