Note 9 - Cash Dividends (Details Textual) - USD ($)	3 Months Ended
Sep. 30, 2018	Sep. 30, 2017	Nov. 07, 2018
Payments of Ordinary Dividends, Common Stock	$ 1,296,000	$ 1,286,000
Dividends Accrued	$ 31,553	$ 29,106
Subsequent Event [Member]
Quarterly Indicated Per Share Dividend Rate			$ 0.05
Annual Indicated per Share Dividend Rate			$ 0.20

Amount of cash outflow in the form of ordinary dividends to common shareholders of the parent entity.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3291-108585

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration