Condensed Consolidated Balance Sheets (Unaudited) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Current assets:
Cash and cash equivalents	$ 110,446	$ 75,104
Short-term investments	93,902	85,521
Accounts receivable, net of allowances of $10 as of September 30, 2013 and $20 as of December 31, 2012	21,957	19,383
Inventories	42,975	32,115
Deferred income tax assets, net - current	19	1
Prepaid expenses and other current assets	1,651	2,177
Total current assets	270,950	214,301
Property and equipment, net	67,221	59,412
Long-term investments	9,847	11,755
Deferred income tax assets, net - long-term	669	669
Other assets	1,353	1,025
Total assets	350,040	287,162
Current liabilities:
Accounts payable	10,406	9,859
Accrued compensation and related benefits	6,708	7,686
Accrued liabilities	9,245	5,915
Total current liabilities	26,359	23,460
Long-term liabilities	1,311
Non-current income tax liabilities	5,039	5,408
Total liabilities	32,709	28,868
Stockholders' equity:
Common stock, $0.001 par value; shares authorized: 150,000; shares issued and outstanding: 38,227 and 35,673 as of September 30, 2013 and December 31, 2012, respectively	235,993	194,079
Retained earnings	75,439	60,040
Accumulated other comprehensive income	5,899	4,175
Total stockholders’ equity	317,331	258,294
Total liabilities and stockholders’ equity	$ 350,040	$ 287,162