Income Taxes - Components of Deferred Tax Assets and Liabilities (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Components of Deferred Tax Assets and Liabilities [Abstract]
Deferred revenue, current	$ 856	$ 860
Intangibles and related other, long-term	159	(580)
Inventory reserve, current	1,871	1,598
Inventory reserve, long-term	0	0
Net operationg loss carryforwards, long-term	667	364
Research and development tax credits, long-term	248	1,033
Accrued expenses, current	140	182
Stock-based compensation, long-term	684	742
Allowance for sales returns and doubtful accounts, current	20	56
Difference in property and equipment basis, long-term	(475)	(646)
Other, current	462	291
Other, long-term	(19)	52
Total net deferred income tax assets, current	3,349	2,987
Total net deferred income tax asset, long-term	1,264	965
Less: Valuation allowance, current	(201)	0
Less: valuation allowance, long-term	(69)	(1,066)
Net deferred income tax asset (liability), current	3,148	2,987
Net deferred income tax asset (liability), long-term	1,195	0
Deferred Tax Liabilities, Net, Noncurrent	$ 0	$ (101)