Note 3 - Certificates of Deposit - Summary of Certificates of Deposit (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Jun. 30, 2017
Under 90 Days [Member]
CDARS	$ 825	$ 3,039
For 91 Days to Six Months [Member]
CDARS	825
Six Months to 1 Year [Member]
CDARS	1,650
Greater than 1 Year [Member]
CDARS

Cost of the investment.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 946
-SubTopic 210
-Section 50
-Paragraph 6
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=63488139&loc=d3e12121-115841

Name:	us-gaap_InvestmentOwnedAtCost
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant