Fair Value and Carrying Value of Financial Instruments and Long-Term Debt (Detail) - USD ($) $ in Thousands	Aug. 31, 2018	May 31, 2018
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Marketable securities	$ 174,038	$ 168,071
Equity securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Marketable securities	149,560	144,555
Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	202,183	244,422
Long-term debt, including current portion	2,270,535	2,174,144
Carrying Value \| Equity securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Marketable securities	149,560	144,555
Carrying Value \| Debt securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Marketable securities	24,478	23,516
Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	202,183	244,422
Long-term debt, including current portion	2,320,331	2,215,458
Fair Value \| Equity securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Marketable securities	149,560	144,555
Fair Value \| Debt securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Marketable securities	$ 24,478	$ 23,516

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

No definition available.

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- Definition

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.

+ References

No definition available.

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- Definition

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=109250915&loc=d3e13433-108611

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- Definition

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.

+ References

No definition available.

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