Fair Value and Carrying Value of Financial Instruments and Long-Term Debt (Detail) - USD ($) $ in Thousands	Feb. 28, 2021	May 31, 2020
Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	$ 249,214	$ 233,416
Marketable equity securities	127,140	87,111
Available-for-sale debt securities	25,628	26,922
Long-term debt, including current portion	2,311,510	2,539,180
Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	249,214	233,416
Marketable equity securities	127,140	87,111
Available-for-sale debt securities	25,628	26,922
Long-term debt, including current portion	$ 2,507,299	$ 2,618,719

Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(6))
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
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-Section 45
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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Fair value portion of debt instrument payable, including, but not limited to, notes payable and loans payable.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=121572278&loc=d3e13433-108611

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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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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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