CREDIT ARRANGEMENTS (Long-term Debt, Including the Deferred Gain from the Termination of the Interest Rate Swaps) (Details) - USD ($) $ in Thousands	May 31, 2017	Aug. 31, 2016
Debt Instrument [Line Items]
Total debt	$ 1,066,762	$ 1,075,641
Less debt issuance costs	3,432	4,224
Total amounts outstanding	1,063,330	1,071,417
Less current maturities	311,654	313,469
Long-term debt	$ 751,676	757,948
2023 Notes
Debt Instrument [Line Items]
Weighted average interest rate	4.875%
Total debt	$ 330,000	330,000
2018 Notes
Debt Instrument [Line Items]
Weighted average interest rate	6.4047%
Total debt	$ 405,406	408,874
2017 Notes
Debt Instrument [Line Items]
Weighted average interest rate	5.7359%
Total debt	$ 300,372	302,601
Other, including equipment notes
Debt Instrument [Line Items]
Total debt	$ 30,984	$ 34,166