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Amount of equity securities categorized neither as held-to-maturity nor as trading.

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Amount 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. Excludes cash and cash equivalents within disposal group and discontinued operation.

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Fair Value and Carrying Value of Financial Instruments and Long-Term Debt (Detail) (USD $) In Thousands, unless otherwise specified	May 31, 2013	May 31, 2012	May 31, 2011	May 31, 2010
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents, carrying value	$ 343,554	$ 315,968	$ 435,011	$ 215,355
Marketable equity securities, carrying value	90,292	83,562
Marketable debt securities, carrying value	22,801	36,567
Long-term debt, including current portion, carrying value	1,373,697	1,115,536
Cash and cash equivalents, fair value	343,554	315,968
Marketable securities, fair value	113,093	120,129
Long-term debt, including current portion, fair value	1,501,850	1,232,180
Equity securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Marketable securities, fair value	90,292	83,562
Fixed securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Marketable securities, fair value	$ 22,801	$ 36,567