UNAUDITED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	Common Stock [Member]	Additional Paid-In Capital [Member]	Treasury Stock [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income [Member]	Total
Balance at Mar. 31, 2019	$ 143	$ 137,243	$ (53,999)	$ 341,137	$ (271)	$ 424,253
Balance (in shares) at Mar. 31, 2019	13,611
Issuance of restricted stock awards	$ 1	0	0	0	0	1
Issuance of restricted stock awards (in shares)	86
Share-based compensation	$ 0	1,919	0	0	0	1,919
Repurchase of common stock	0	0	$ (13,455)	0	0	(13,455)
Repurchase of common stock (in shares)			(188)
Net earnings	0	0	$ 0	16,188	0	16,188
Foreign currency translation adjustment	0	0	0	0	(263)	(263)
Balance at Jun. 30, 2019	$ 144	139,162	(67,454)	357,325	(534)	428,643
Balance (in shares) at Jun. 30, 2019	13,509
Balance at Mar. 31, 2020	$ 144	145,197	(68,424)	410,219	(991)	$ 486,145
Balance (in shares) at Mar. 31, 2020	13,500					13,500
Issuance of restricted stock awards	$ 1	0	0	0	0	$ 1
Issuance of restricted stock awards (in shares)	91
Share-based compensation	$ 0	1,885	0	0	0	1,885
Repurchase of common stock	0	0	$ (2,703)	0	0	(2,703)
Repurchase of common stock (in shares)			(38)
Net earnings	0	0	$ 0	17,360	0	17,360
Foreign currency translation adjustment	0	0	0	0	37	37
Balance at Jun. 30, 2020	$ 145	$ 147,082	$ (71,127)	$ 427,579	$ (954)	$ 502,725
Balance (in shares) at Jun. 30, 2020	13,553					13,553