Income Tax (Details Textual) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2011
Income Tax (Textual) [Abstract]
Recognized federal research and development tax credits	$ 1,461	$ 1,055	$ 927
State research and development tax credits	145	165	119
Qualified production activities deduction under Section 199 of the Internal Revenue Code	9,032	10,025	8,134
Accrued interest related to income tax	$ 118	$ 75
Period within which the company does not anticipate total unrecognized tax benefits to change	within the next twelve months