Note 8 - Cash Dividends (Details Textual) - USD ($)	12 Months Ended
Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2016	Aug. 31, 2018
Payments of Ordinary Dividends, Common Stock	$ 5,154,000	$ 5,048,000	$ 4,214,000
Dividends Accrued	$ 50,621	$ 30,067
Quarterly Indicated Per Share Dividend Rate				$ 0.05

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

Name:	us-gaap_PaymentsOfDividendsCommonStock
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration