Income Taxes (Details 1) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Deferred income tax assets:
Net operating loss carryforwards and credits	$ 24,883	$ 25,588
Acquired intangible assets	8,121	8,943
Reserves and accruals	2,149	2,779
Share-based compensation	2,438	1,938
Depreciation	268	160
Total deferred income tax assets	37,859	39,408
Deferred income tax liabilities:
Acquired intangible assets	(213)	(405)
Other	(6)	(12)
Total deferred income tax liabilities	(219)	(417)
Valuation allowance	(37,726)	(39,049)	(39,373)	(17,492)
Deferred income tax liability, net	$ (86)	$ (58)