UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - 6 months ended Sep. 30, 2017 - 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, 2017	$ 142	$ 123,536	$ 0	$ 222,823	$ (583)	$ 345,918
Balance (in shares) at Mar. 31, 2017	14,161					14,161
Issuance of restricted stock awards	$ 0	0	0	0	0	$ 0
Issuance of restricted stock awards (in shares)	68
Share-based compensation	$ 0	3,180	0	0	0	3,180
Repurchase of common stock	$ 0	0	(4,383)	0	0	(4,383)
Repurchase of common stock (in shares)	(58)
Net earnings	$ 0	0	0	30,644	0	30,644
Foreign currency translation adjustment	0	0	0	0	703	703
Balance at Sep. 30, 2017	$ 142	$ 126,716	$ (4,383)	$ 253,467	$ 120	$ 376,062
Balance (in shares) at Sep. 30, 2017	14,171					14,171