Note 2 - Summary of Significant Accounting Policies - Allowance for Ship and Debit (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2015
Beginning Balance	$ 866	$ 1,059	$ 1,071
Additions	7,363	4,479	5,765
Deductions	(6,680)	(4,672)	(5,777)
Ending Balance	$ 1,549	$ 866	$ 1,059