Condensed Consolidated Balance Sheets (Unaudited) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Current assets:
Cash and cash equivalents	$ 78,731	$ 96,371
Short-term investments	102,197	77,827
Accounts receivable, net of allowances of $5 in 2012 and 2011	19,947	15,097
Inventories	21,547	20,104
Deferred income tax assets, net - current	646	421
Prepaid expenses and other current assets	2,352	1,685
Total current assets	225,420	211,505
Property and equipment, net	51,437	47,794
Long-term investments	13,665	13,675
Deferred income tax assets, net - long-term	19	239
Other assets	639	654
Total assets	291,180	273,867
Current liabilities:
Accounts payable	14,573	8,904
Accrued compensation and related benefits	6,746	9,321
Accrued liabilities	10,150	7,845
Total current liabilities	31,469	26,070
Non-current income tax liabilities	4,930	4,920
Total liabilities	36,399	30,990
Stockholders' equity:
Common stock, $0.001 par value, $34 in 2012 and 2011; shares authorized: 150,000,000; shares issued and outstanding: 34,410,896 and 33,826,032 in 2012 and 2011, respectively	167,773	159,336
Retained earnings	82,943	79,948
Accumulated other comprehensive income	4,065	3,593
Total stockholders’ equity	254,781	242,877
Total liabilities and stockholders’ equity	$ 291,180	$ 273,867