Condensed Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - USD ($) $ in Thousands	Dec. 31, 2019	Mar. 31, 2019
Accounts receivable, allowance for doubtful accounts	$ 13	$ 27
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred, authorized shares (in shares)	10,000,000	10,000,000
Preferred, issued shares (in shares)	0	0
Preferred outstanding, shares (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.02	$ 0.02
Common stock, shares authorized (in shares)	50,000,000	50,000,000
Common stock, shares issued (in shares)	5,925,717	5,879,710
Common stock, shares outstanding (in shares)	5,925,717	5,879,710