Condensed Consolidated Balance Sheets (Unaudited) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Current assets:
Cash and cash equivalents	$ 107,863	$ 101,213
Short-term investments	133,012	125,126
Accounts receivable, net of allowances of $0 as of June 30, 2014 and December 31, 2013	21,420	23,730
Inventories	41,198	39,737
Deferred income tax assets, net	295	294
Prepaid expenses and other current assets	2,509	1,986
Total current assets	306,297	292,086
Property and equipment, net	64,447	64,837
Long-term investments	9,848	9,860
Deferred income tax assets, net	476	481
Other long-term assets	5,586	1,644
Total assets	386,654	368,908
Current liabilities:
Accounts payable	13,759	10,694
Accrued compensation and related benefits	12,606	10,419
Accrued liabilities	15,605	17,376
Total current liabilities	41,970	38,489
Income tax liabilities	5,758	5,542
Other long-term liabilities	4,298	1,478
Total liabilities	52,026	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: 38,774 and 38,291 as of June 30, 2014 and December 31, 2013, respectively	236,519	234,201
Retained earnings	92,269	82,938
Accumulated other comprehensive income	5,840	6,260
Total stockholders’ equity	334,628	323,399
Total liabilities and stockholders’ equity	$ 386,654	$ 368,908