Marketable Securities - Additional Information (Detail) - USD ($) $ in Millions	May 31, 2021	May 31, 2020
Investments Debt And Equity Securities [Abstract]
Available-for-sale debt securities, current	$ 3.9	$ 7.6
Available-for-sale debt securities, long-term	22.8	19.3
Equity securities	$ 142.1	$ 87.1

Amount of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

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-Publisher FASB
-Name Accounting Standards Codification
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Amount of investment in marketable security, classified as current.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
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Amount of investment in marketable security, classified as noncurrent.

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