Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Mar. 31, 2013
Current assets:
Cash and cash equivalents	$ 11,727	$ 9,451
Short-term marketable securities	55,725	67,256
Accounts receivable, net	20,983	22,946
Inventories	16,513	14,930
Prepaid expenses and other current assets	1,737	2,022
Total current assets	106,685	116,605
Long-term marketable securities	20,588	11,406
Property and equipment, net	6,479	6,549
Goodwill	35,932	35,410
Other assets	779	29
Total assets	170,463	169,999
Current liabilities:
Accounts payable	6,270	7,696
Accrued expenses	12,829	15,162
Deferred revenue	3,993	4,198
Total current liabilities	23,092	27,056
Long-term deferred tax liability	5,781	5,554
Other long-term liabilities	285	309
Total liabilities	29,158	32,919
Commitments and contingencies
Stockholders' equity:
Class B Preferred Stock, $.01 par value Authorized - 1,000,000 shares; Issued and outstanding - none
Common stock, $.01 par value Authorized - 100,000,000 shares; Issued - 40,218,485 shares at June 30, 2013 and 39,788,383 shares at March 31, 2013; Outstanding - 39,012,118 shares at June 30, 2013 and 38,601,384 shares at March 31, 2013	401	397
Additional paid in capital	420,674	414,810
Accumulated deficit	(259,984)	(258,261)
Treasury stock at cost - 1,206,367 shares at June 30, 2013 and 1,186,999 shares at March 31, 2013	(16,554)	(16,129)
Accumulated other comprehensive loss	(3,232)	(3,737)
Total stockholders' equity	141,305	137,080
Total liabilities and stockholders' equity	$ 170,463	$ 169,999