Condensed Consolidated Balance Sheets (Unaudited) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Current assets:
Cash and cash equivalents	$ 18,043	$ 23,560
Short-term investments	60,891	58,585
Trade, note and other accounts receivable, net of allowances of $0 at March 31, 2012 and of $41 at December 31, 2011	19,600	18,561
Inventories	19,843	18,070
Prepaid expenses and other current assets	7,696	7,114
Deferred income tax assets	2,546	2,202
Total current assets	128,619	128,092
Property, plant and equipment, net	14,018	14,449
Long-term investments	32,792	32,677
Goodwill	18,389	18,389
Other intangible assets, net of amortization of $2,480 at March 31, 2012 and $2,344 at December 31, 2011	6,305	6,441
Deferred income taxes and other long-term assets	28,478	25,773
Total assets	228,601	225,821
Current liabilities:
Accounts payable	5,029	4,857
Accrued payroll and related liabilities	4,745	4,205
Other accrued liabilities	12,314	9,887
Customer advances	5,797	5,040
Total current liabilities	27,885	23,989
Other long-term liabilities	9,953	9,922
Stockholders' equity:
Common stock, $0.001 par value	23	23
Additional paid-in capital	148,224	146,307
Accumulated other comprehensive income	511	414
Retained earnings	42,005	45,166
Total stockholders' equity	190,763	191,910
Total liabilities and stockholders' equity	$ 228,601	$ 225,821