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, 2013	$ 129	$ 99,641	$ (67,306)	$ 205,358	$ 410	$ 238,232
Balance (in shares) at Mar. 31, 2013	8,150
Issuance of shares for option exercises	$ 0	559	0	0	0	559
Issuance of shares for option exercises (in shares)	40
Excess tax benefit of share - based compensation	$ 0	1,762	0	0	0	1,762
Issuance of restricted stock awards	$ 1	0	0	0	0	1
Issuance of restricted stock awards (in shares)	87
Share-based compensation		3,962	0	6	0	3,968
Repurchase of common stock	$ 0	0	(13,188)	0	0	(13,188)
Repurchase of common stock (in shares)	(241)
Net earnings	$ 0	0	0	35,273	0	35,273
Foreign currency translation adjustment	0	0	0	0	(224)	(224)
Balance at Mar. 31, 2014	$ 130	105,924	(80,494)	240,637	186	266,383
Balance (in shares) at Mar. 31, 2014	8,036
Excess tax benefit of share - based compensation	$ 0	564	0	0	0	564
Issuance of restricted stock awards	$ 1	0	0	0	0	1
Issuance of restricted stock awards (in shares)	88
Share-based compensation		4,584	0	0	0	4,584
Repurchase of common stock	$ 0	0	(37,685)	0	0	(37,685)
Repurchase of common stock (in shares)	(735)
Net earnings	$ 0	0	0	45,840	0	45,840
Foreign currency translation adjustment	0	0	0	0	(425)	(425)
Balance at Mar. 31, 2015	$ 131	111,072	(118,179)	286,477	(239)	$ 279,262
Balance (in shares) at Mar. 31, 2015	7,389					7,389
Excess tax benefit of share - based compensation	$ 0	728	0	0	0	$ 728
Issuance of restricted stock awards	$ 1	0	0	0	0	1
Issuance of restricted stock awards (in shares)	123
Share-based compensation		5,711	0	0	0	5,711
Repurchase of common stock	$ 0	0	(11,339)	0	0	(11,339)
Repurchase of common stock (in shares)	(147)
Net earnings	$ 0	0	0	44,747	0	44,747
Foreign currency translation adjustment	0	0	0	0	(232)	(232)
Balance at Mar. 31, 2016	$ 132	$ 117,511	$ (129,518)	$ 331,224	$ (471)	$ 318,878
Balance (in shares) at Mar. 31, 2016	7,365					7,365