XML 41 R36.htm IDEA: XBRL DOCUMENT v2.4.0.6
Fair Value of Financial Instruments (Details2) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2012
Dec. 31, 2011
Fair Value
   
Fair value hierarchy for its financial assets    
Money market funds $ 1,407 $ 2,792
Total assets 40,389 20,742
Fair Value | U.S. government debt securities
   
Fair value hierarchy for its financial assets    
Available-for-sale securities 22,289 10,557
Fair Value | Corporate notes
   
Fair value hierarchy for its financial assets    
Available-for-sale securities 16,226 7,393
Fair Value | Certificates of deposit
   
Fair value hierarchy for its financial assets    
Available-for-sale securities 467  
Level 1
   
Fair value hierarchy for its financial assets    
Money market funds 1,407 2,792
Total assets 1,407 2,792
Level 2
   
Fair value hierarchy for its financial assets    
Total assets 38,982 17,950
Level 2 | U.S. government debt securities
   
Fair value hierarchy for its financial assets    
Available-for-sale securities 22,289 10,557
Level 2 | Corporate notes
   
Fair value hierarchy for its financial assets    
Available-for-sale securities 16,226 7,393
Level 2 | Certificates of deposit
   
Fair value hierarchy for its financial assets    
Available-for-sale securities $ 467