CONSOLIDATED BALANCE SHEETS (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2019	Mar. 31, 2019	Sep. 30, 2018
Statement of Financial Position [Abstract]
Allowances for accounts receivable	$ 231	$ 2,198	$ 1,757
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01	$ 0.01
Preferred stock, shares authorized	1,000,000	1,000,000	1,000,000
Preferred stock, shares issued	0	0	0
Common stock, par value (in dollars per share)	$ 0.10	$ 0.10	$ 0.10
Common stock, shares authorized	25,000,000	25,000,000	25,000,000
Common stock, shares issued	14,703,084	14,703,084	14,703,084
Treasury stock, shares	5,824,025	5,865,846	5,813,926