Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012	Mar. 31, 2011
Current assets:
Cash and cash equivalents	$ 5,990	$ 5,831
Short-term marketable securities	71,233	54,481
Accounts receivable, net	20,458	15,376
Inventories	11,142	7,505
Prepaid expenses and other current assets	1,716	1,544
Total current assets	110,539	84,737
Property and equipment, net	6,378	6,273
Intangible assets, net	115	1,632
Goodwill	36,846	38,946
Other long-term assets	33
Total assets	153,911	131,588
Current liabilities:
Accounts payable	6,910	6,283
Accrued expenses	12,480	14,078
Deferred revenue	3,025	1,982
Total current liabilities	22,415	22,343
Long-term deferred tax liability	4,799	4,010
Other long-term liabilities	400	492
Total liabilities	27,614	26,845
Commitments and contingencies (Note 10)
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-39,323,708 shares at March 31, 2012 and 37,756,719 shares at March 31, 2011; Outstanding-39,272,754 shares at March 31, 2012 and 37,705,765 shares at March 31, 2011	393	377
Additional paid in capital	401,771	379,218
Accumulated deficit	(273,275)	(274,770)
Treasury stock at cost-50,954 shares	(827)	(827)
Accumulated other comprehensive (loss) income	(1,765)	745
Total stockholders' equity	126,297	104,743
Total liabilities and stockholders' equity	$ 153,911	$ 131,588