Balance Sheet Components (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Cash and cash equivalents:
Cash			$ 5,876	$ 18,653
Money market instruments and funds			281	4,070
Cash and Cash Equivalents, At Carrying Value			6,157	22,723	$ 18,603	$ 4,793
Accounts receivable, net:
Accounts receivable			12,668	10,927
Less: Allowance for doubtful accounts and sales returns	$ (121)	$ (121)	(121)	(121)	(121)
Accounts Receivable, Net, Current			12,547	10,806
Allowance for doubtful accounts and sales returns:
Balance at beginning of year	$ 121	$ 121
Utilized
Balance at end of year	$ 121	$ 121
Inventories:
Finished goods			3,958	3,191
Work-in-process			4,705	3,430
Raw materials			3,667	5,052
Inventories			12,330	11,673
Inventory reserves:
Inventory reserves			1,411	2,368	$ 2,400
Accrued expenses and other current liabilities:
Compensation costs			4,325	5,016
Professional fees			24	55
Outside commissions			146	143
Royalties			82	135
ESPP			147	138
Deferred rent			29	33
Warranty			70	82
Operating related (Taiwan and China)			483	417
Income tax			2,888	$ 2,204
Stock buyback			851
Other			465	$ 476
Accrued Liabilities, Current, Total			9,510	8,699
Long-term liabilities:
Income tax payable			1,581	376
Accrued pension liability (Taiwan)			613	602
Liabilities, Noncurrent, Total			2,194	978
Accumulated other comprehensive Income:
Cumulative translation adjustments			172	1,447
Unrealized loss on short-term investments			(1)	(10)
Accumulated Other Comprehensive Income (Loss), Net Of Tax			171	1,437
Finished Goods [Member]
Inventory reserves:
Inventory reserves			520	647
Work-In-Process [Member]
Inventory reserves:
Inventory reserves			296	460
Raw Materials [Member]
Inventory reserves:
Inventory reserves			$ 595	$ 1,261