CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Mar. 31, 2012
Current assets:
Cash and cash equivalents	$ 47,427	$ 45,843
Short-term investments	22,644	21,689
Receivables (net of allowances of $225 at December 31, 2012 and $283 at March 31, 2012)	36,094	30,694
Inventories	25,069	19,597
Prepaid expenses and other current assets	7,067	5,423
Net deferred tax assets, current	4,356	4,151
Total current assets	142,657	127,397
Long-term investments	21,712	23,442
Investment in unconsolidated affiliate	2,613	2,626
Property and equipment, net	25,512	24,296
Intangible assets, net	3,515	3,990
Other assets	97	85
Total assets	196,106	181,836
Current liabilities:
Accounts payable	11,536	6,381
Accrued payroll and related expenses	8,380	6,336
Accrued taxes	229	266
Other accrued liabilities	2,314	1,991
Deferred revenue	1,388	1,212
Warranty reserve	993	1,245
Total current liabilities	24,840	17,431
Non-current liabilities:
Deferred rent	712	641
Net deferred tax liabilities	159	199
Deferred revenue	3,517	2,396
Warranty reserve	473	601
Notes payable, less current portion	707	783
Total non-current liabilities	5,568	4,620
Total liabilities	30,408	22,051
Commitments and contingencies (Note 9)
Shareholders' equity:
Preferred stock, no par value: 5,000,000 shares authorized; no shares issued and outstanding	0	0
Common stock, no par value: 35,000,000 shares authorized; 22,023,000 and 21,699,000 shares issued and outstanding at December 31, 2012 and at March 31, 2012, respectively	117,217	110,063
Retained earnings	48,435	49,697
Accumulated other comprehensive income	46	25
Total shareholders' equity	165,698	159,785
Total liabilities and shareholders' equity	$ 196,106	$ 181,836