Note 4 - Fair Value (Details Textual) - USD ($)	3 Months Ended		12 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Mar. 31, 2016
Other than Temporary Impairment Losses, Investments	$ 151,000	$ 0
Auction Rate Preferred Securities Percentage Collateralized	100.00%		100.00%
Collateralized Asset Value Exceeding Value of ARPS Percentage	200.00%		200.00%
Debt, Long-term and Short-term, Combined Amount	$ 79,000,000		$ 87,100,000