UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - 6 months ended Sep. 30, 2018 - 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, 2018	$ 142	$ 130,000	$ (36,016)	$ 277,945	$ 532	$ 372,603
Balance (in shares) at Mar. 31, 2018	13,761					13,761
Issuance of restricted stock awards	$ 1	0	0	0	0	$ 1
Issuance of restricted stock awards (in shares)	77
Share-based compensation	$ 0	3,561	0	0	0	3,561
Repurchase of common stock	$ 0	0	(9,364)	0	0	(9,364)
Repurchase of common stock (in shares)	(111)
Net earnings	$ 0	0	0	33,276	0	33,276
Foreign currency translation adjustment	0	0	0	0	(800)	(800)
Balance at Sep. 30, 2018	$ 143	$ 133,561	$ (45,380)	$ 311,221	$ (268)	$ 399,277
Balance (in shares) at Sep. 30, 2018	13,727					13,727