Note 5 - Marketable Securities (Details Textual)	3 Months Ended	12 Months Ended
Jun. 30, 2016 USD ($)	Mar. 31, 2016 USD ($)
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss	$ 0	$ 10,824
Number of Other-than-temporarily Impaired Marketable Securities	0

Amount of unrealized loss on securities classified as available-for-sale.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 6
-Subparagraph (a)(2)
-URI http://asc.fasb.org/extlink&oid=73527792&loc=d3e27290-111563

Name:	us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAggregateLosses
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration