Note 3 - Fair Value (Details Textual) - USD ($)	3 Months Ended			6 Months Ended
	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Mar. 31, 2017
Other than Temporary Impairment Losses, Investments	$ 0		$ 0	$ 0	$ 151,000
Debt, Long-term and Short-term, Combined Amount	77,900,000			77,900,000		$ 77,800,000
Impairment of Intangible Assets, Finite-lived		$ 1,400,000
Fair Value, Inputs, Level 3 [Member]
Assets, Fair Value Disclosure, Recurring	0			0		0
Liabilities, Fair Value Disclosure, Recurring	$ 0			$ 0		$ 0