Note 4 - Fair Value (Details Textual) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Mar. 31, 2015
Other than Temporary Impairment Losses, Investments	$ 0	$ 945	$ 454	$ 945
Auction Rate Preferred Securities Percentage Collateralized	100.00%		100.00%
Collateralized Asset Value Exceeding Value of ARPS Percentage	300.00%		300.00%
Debt, Long-term and Short-term, Combined Amount	$ 88,100		$ 88,100		$ 49,200