Balance Sheet Information (Details 2) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Summary of Accrued liabilities
Inventory receipts	$ 1,756	$ 2,191
Paid time off	1,143	1,067
Professional fees	852	269
Payroll, bonuses, and other employee benefits	727	873
Warranties	277	270
Real estate taxes	213	170
Employee stock purchase plan	122	276
Sales tax	107	156
Deferred liabilities	105	127
Restructuring	77	0
Other	640	517
Total	$ 6,019	$ 5,916