Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2020	Mar. 31, 2020
Allowance for doubtful accounts receivable	$ 1,209	$ 1,634
Common stock, stated value	$ 0.30	$ 0.30
Common stock, shares authorized	80,000,000	80,000,000
Common stock, shares issued	31,606,831	31,606,831
Common stock, shares outstanding	23,588,178	23,609,398
Treasury shares	8,018,653	7,997,433
Series A Convertible Preferred Stock [Member]
Preferred Stock, No Par Value