Condensed Consolidated Balance Sheets (Unaudited) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Current assets:
Cash and cash equivalents	$ 88,885	$ 101,213
Short-term investments	139,750	125,126
Accounts receivable, net of allowances of $0 as of March 31, 2014 and December 31, 2013	22,057	23,730
Inventories	39,829	39,737
Deferred income tax assets, net	292	294
Prepaid expenses and other current assets	2,444	1,986
Total current assets	293,257	292,086
Property and equipment, net	65,897	64,837
Long-term investments	9,843	9,860
Deferred income tax assets, net	476	481
Other long-term assets	5,159	1,644
Total assets	374,632	368,908
Current liabilities:
Accounts payable	11,748	10,694
Accrued compensation and related benefits	10,332	10,419
Accrued liabilities	8,559	17,376
Total current liabilities	30,639	38,489
Income tax liabilities	5,652	5,542
Other long-term liabilities	3,674	1,478
Total liabilities	39,965	45,509
Commitments and contingencies (Notes 6 and 8)
Stockholders' equity:
Common stock, $0.001 par value; shares authorized: 150,000; shares issued and outstanding: 38,672 and 38,291 as of March 31, 2014 and December 31, 2013, respectively	237,059	234,201
Retained earnings	91,956	82,938
Accumulated other comprehensive income	5,652	6,260
Total stockholders’ equity	334,667	323,399
Total liabilities and stockholders’ equity	$ 374,632	$ 368,908