Quarterly report pursuant to Section 13 or 15(d)

Fair Value Measurements (Details)

v2.4.0.6
Fair Value Measurements (Details) (Fair Value, Measurements, Recurring [Member], USD $)
In Thousands, unless otherwise specified
Mar. 31, 2013
Assets  
Total Assets $ 64,903
Cash [Member]
 
Assets  
Total Assets 2,612
Money market securities [Member]
 
Assets  
Total Assets 16,330
Government securities [Member]
 
Assets  
Total Assets   
Corporate bonds and commercial paper [Member]
 
Assets  
Total Assets 45,961
Warrants [Member]
 
Liabilities  
Liabilities 1,988
Level 1 [Member]
 
Assets  
Total Assets 18,942
Level 1 [Member] | Cash [Member]
 
Assets  
Total Assets 2,612
Level 1 [Member] | Money market securities [Member]
 
Assets  
Total Assets 16,330
Level 1 [Member] | Government securities [Member]
 
Assets  
Total Assets   
Level 1 [Member] | Corporate bonds and commercial paper [Member]
 
Assets  
Total Assets   
Level 1 [Member] | Warrants [Member]
 
Liabilities  
Liabilities   
Level 2 [Member]
 
Assets  
Total Assets 45,961
Level 2 [Member] | Cash [Member]
 
Assets  
Total Assets   
Level 2 [Member] | Money market securities [Member]
 
Assets  
Total Assets   
Level 2 [Member] | Government securities [Member]
 
Assets  
Total Assets   
Level 2 [Member] | Corporate bonds and commercial paper [Member]
 
Assets  
Total Assets 45,961
Level 2 [Member] | Warrants [Member]
 
Liabilities  
Liabilities   
Level 3 [Member]
 
Assets  
Total Assets   
Level 3 [Member] | Cash [Member]
 
Assets  
Total Assets   
Level 3 [Member] | Money market securities [Member]
 
Assets  
Total Assets   
Level 3 [Member] | Government securities [Member]
 
Assets  
Total Assets   
Level 3 [Member] | Corporate bonds and commercial paper [Member]
 
Assets  
Total Assets   
Level 3 [Member] | Warrants [Member]
 
Liabilities  
Liabilities $ 1,988