Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - USD ($)	Dec. 31, 2016	Mar. 31, 2016
Allowance for doubtful accounts	$ 437,000	$ 426,000
Preferred stock, par value (in dollars per share)	$ 1	$ 1
Preferred stock, authorized (in shares)	50,000	50,000
Common stock, par value (in dollars per share)	$ 0.25	$ 0.25
Common stock, authorized (in shares)	4,000,000	4,000,000
Common stock, issued (in shares)	2,042,789	2,372,527
Common stock, outstanding (in shares)	2,042,789	2,372,527