Note 4 - Fair Value (Details Textual) xbrli-pure in Thousands, $ in Thousands	12 Months Ended
	Mar. 31, 2017 USD ($)	Mar. 31, 2016 USD ($)	Mar. 31, 2015 USD ($)
Debt, Long-term and Short-term, Combined Amount	$ 77,800	$ 87,100
Other than Temporary Impairment Losses, Investments	$ 151	$ 454	$ 1,900
Derivative, Number of Instruments Held	0	0
Fair Value, Inputs, Level 3 [Member]
Assets, Fair Value Disclosure, Recurring	$ 0	$ 0
Liabilities, Fair Value Disclosure, Recurring	$ 0	$ 0