STOCKHOLDERS' EQUITY (Schedule of Dividends) (Details) - $ / shares						3 Months Ended		9 Months Ended
	Feb. 28, 2018	Jan. 24, 2018	Aug. 31, 2017	Feb. 28, 2017	Feb. 01, 2017	May 31, 2018	May 31, 2017	May 31, 2018	May 31, 2017
Dividends Payable [Line Items]
Amount								$ 0.70	$ 0.70
2018 Dividend Declared [Member]
Dividends Payable [Line Items]
Declared								Jan. 24, 2018
Amount		$ 0.70
2017 Dividend Declared [Member]
Dividends Payable [Line Items]
Declared								Feb. 01, 2017
Amount					$ 0.70
2018 First Dividend Paid [Member]
Dividends Payable [Line Items]
Record Date								Feb. 14, 2018
Date Paid								Feb. 28, 2018
Payment Amount	$ 0.35
2018 Second Dividend Paid [Member]
Dividends Payable [Line Items]
Record Date								Aug. 15, 2018
Date Payable								Aug. 31, 2018
Payment Amount								$ 0.35
2017 First Dividend Paid [Member]
Dividends Payable [Line Items]
Record Date								Feb. 15, 2017
Date Paid								Feb. 28, 2017
Payment Amount				$ 0.35
2017 Second Dividend Paid [Member]
Dividends Payable [Line Items]
Record Date								Aug. 15, 2017
Date Paid								Aug. 31, 2017
Payment Amount			$ 0.35