Condensed Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Mar. 31, 2014
Current assets:
Cash and cash equivalents	$ 34,740	$ 20,916
Short-term marketable securities	52,458	55,663
Accounts receivable, net	22,763	24,357
Inventories	13,920	13,948
Prepaid expenses and other current assets	3,334	3,082
Total current assets	127,215	117,966
Long-term marketable securities	33,760	41,761
Property and equipment, net	6,716	6,889
Goodwill	37,694	37,990
Other assets	801	801
Total assets	206,186	205,407
Current liabilities:
Accounts payable	6,759	7,746
Accrued expenses	17,015	17,899
Deferred revenue	5,200	4,766
Total current liabilities	28,974	30,411
Long-term deferred tax liability	6,640	6,415
Other long-term liabilities	222	228
Total liabilities	35,836	37,054
Commitments and contingencies (Note 9)
Stockholders' equity:
Class B Preferred Stock, $.01 par value Authorized - 1,000,000 shares; Issued and outstanding - none	0	0
Common stock, $.01 par value Authorized - 100,000,000 shares; Issued - 41,619,312 shares at June 30, 2014 and 41,122,695 shares at March 31, 2014; Outstanding - 40,365,369 shares at June 30, 2014 and 39,916,328 shares at March 31, 2014	415	411
Additional paid in capital	441,260	436,136
Accumulated deficit	(252,619)	(250,910)
Treasury stock at cost - 1,253,943 shares at June 30, 2014 and 1,206,367 shares at March 31, 2014	(17,567)	(16,554)
Accumulated other comprehensive loss	(1,139)	(730)
Total stockholders' equity	170,350	168,353
Total liabilities and stockholders' equity	$ 206,186	$ 205,407