Goodwill and Other Intangibles - Schedule of activity in goodwill (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended	12 Months Ended
Nov. 30, 2022	Feb. 28, 2023	Feb. 28, 2022	May 31, 2022	May 31, 2021
Goodwill [Roll Forward]
Gross goodwill				$ 164.9	$ 165.9
Accumulated impairment				(39.6)	$ (39.6)
Beginning balance		$ 125.3	$ 126.3	126.3
Additions	$ 7.0	7.0	0.0	0.0
Foreign currency translation		(0.4)	(0.6)	(1.0)
Ending balance		$ 131.9	$ 125.7	$ 125.3

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Amount of increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination.

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Amount of foreign currency translation gain (loss) which increases (decreases) an asset representing future economic benefits from other assets acquired in a business combination that are not individually identified and separately recognized.

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Amount before accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Amount of accumulated impairment loss for an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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