Revenue Recognition - Contract Assets, Liabilities and Performance Obligations (Details) - USD ($) $ in Millions	3 Months Ended				12 Months Ended
	Aug. 31, 2025	Feb. 28, 2025	Aug. 31, 2024	May 31, 2024	May 31, 2025
Contract assets and liabilities
Contract assets - current	$ 146.7				$ 140.3
Contract assets - non-current	33.2				28.4
Contract liabilities:
Deferred revenue - current	(32.3)				(40.3)
Deferred revenue on long-term contracts	(8.4)				(6.4)
Net contract assets	139.2				122.0
Change in contract assets - current	6.4
Change in contract assets - non-current	4.8
Change in deferred revenue - current	8.0
Change in deferred revenue on long-term contracts	(2.0)
Change in net contract assets	17.2
Change in contract assets and revenue	6.4		$ 24.5
Accounts receivable, net	363.5				354.8
Changes in deferred revenue
Deferred revenue at beginning of period	(46.7)		(21.9)		(21.9)
Revenue deferred	(87.0)		(84.4)
Revenue recognized	93.7		74.2
Other	(0.7)		3.9
Deferred revenue at end of period	(40.7)		(28.2)	$ (21.9)	(46.7)
Remaining Performance Obligations
Remaining performance obligation	$ 490.0
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-03-01
Remaining Performance Obligations
Remaining performance obligation (as a percent)	75.00%
Expected timing of satisfaction of remaining performance obligation	12 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-03-01
Remaining Performance Obligations
Remaining performance obligation (as a percent)	20.00%
Expected timing of satisfaction of remaining performance obligation	12 months
Termination settlement proposal
Contract liabilities:
Contract assets with customer		$ 13.5
Termination amount for equipment and other costs		$ 1.0
Air Line Customers | Termination Of Power By The Hour Program
Contract liabilities:
Termination charge				$ 4.8
Change in contract assets and revenue					7.8
Change in contract revenue					7.8
Repair reserves					2.5
Obligation to purchase the rotable assets					5.5
Asset purchase obligation of purchase price					$ 18.7
Accounts receivable, net	$ 33.5
Contract assets with customer	3.2
Air Line Customers | Termination Of Power By The Hour Program | Past Due
Contract liabilities:
Accounts receivable, net	9.0
U.S. Government Customer | Next Generation Pallet Contract
Contract liabilities:
Contract assets with customer	$ 9.5
Equipment and inventory expensed			$ 12.7