Activity Related to Unrecognized Tax Benefits (Detail) - USD ($) $ in Millions	12 Months Ended
May 31, 2020	May 31, 2019	May 31, 2018
Income Tax Disclosure [Abstract]
Unrecognized tax benefits, beginning balance	$ 8.1	$ 14.1	$ 13.2
Additions based on tax positions related to current year		0.1	5.1
Additions for tax positions of prior years	2.0	2.0
Reductions for tax positions of prior years	(0.9)	(7.9)	(4.5)
Foreign currency translation	(0.2)	(0.2)
Foreign currency translation			0.3
Unrecognized tax benefits, ending balance	$ 9.0	$ 8.1	$ 14.1

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Amount of unrecognized tax benefits.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 45
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Amount of decrease in unrecognized tax benefits resulting from foreign currency translation.

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Amount of decrease in unrecognized tax benefits resulting from tax positions taken in prior period tax returns.

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Amount of increase in unrecognized tax benefits resulting from tax positions that have been or will be taken in current period tax return.

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Amount of increase in unrecognized tax benefits resulting from foreign currency translation.

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Amount of increase in unrecognized tax benefits resulting from tax positions taken in prior period tax returns.

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