CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2014	Dec. 31, 2013
Income Statement [Abstract]
Net sales	$ 23,239	$ 22,628	$ 58,829	$ 57,660
Cost of sales	13,395	14,189	36,434	37,003
Gross profit	9,844	8,439	22,395	20,657
Selling, general, and administrative expenses	3,578	3,198	11,246	9,739
Engineering expense	1,071	2,516	5,117	6,245
Operating income	5,195	2,725	6,032	4,673
Interest expense	8	8	24	41
Other (income) expense – net	(1,200)	23	(1,138)	74
Income before incomes taxes	6,387	2,694	7,146	4,558
Income tax (benefit) provision	(2,657)	1,024	(2,376)	1,732
Net income	$ 9,044	$ 1,670	$ 9,522	$ 2,826
Earnings per common share:
Basic net income per share	$ 0.92	$ 0.17	$ 0.98	$ 0.29
Diluted net income per share	$ 0.91	$ 0.17	$ 0.96	$ 0.29
Weighted-average basic shares outstanding	9,816,000	9,667,000	9,766,000	9,625,000
Weighted-average diluted shares outstanding	9,963,000	9,797,000	9,945,000	9,733,000