Note 8 - Stockholders' Equity - Schedule of Dividends Payable (Details) - $ / shares				3 Months Ended	9 Months Ended
Apr. 25, 2018	Jan. 24, 2018	Nov. 20, 2017	May 31, 2018	May 31, 2017	May 31, 2018	May 31, 2017
Declaration date	Apr. 25, 2018	Jan. 24, 2018	Nov. 20, 2017
Amount (in dollars per share)	$ 0.10	$ 0.10	$ 0.10	$ 0.10	$ 0	$ 0.30	$ 0
Record date	May 09, 2018	Feb. 08, 2018	Dec. 08, 2017
Payable date	May 23, 2018	Feb. 21, 2018	Dec. 21, 2017

Aggregate dividends declared during the period for each share of common stock outstanding.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4304-108586

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