Intangible Assets (Details) (USD $)
In Thousands, unless otherwise specified
12 Months Ended
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2011
Intangible assets      
Trademarks $ 40 $ 40  
Total intangible assets 9,157 7,358  
Less patent amortization (1,302) (687)  
Intangible assets, net 7,855 6,671  
Amortization expense 615 588 81
2014 730    
2015 699    
2016 627    
2017 580    
2018 500    
Thereafter 4,679    
Total 7,815    
Maximum
     
Intangible assets      
Useful life 20 years    
Patents [Member] | Symyx asset purchase transaction
     
Intangible assets      
Average estimated remaining amortization period 4 years    
Patents [Member] | Maximum
     
Intangible assets      
Useful life   20 years  
Patents issued
     
Intangible assets      
Finite-lived, gross 4,893 3,932  
Average estimated amortization period from the date of patents issuance 17 years    
Patents pending
     
Intangible assets      
Finite-lived, gross $ 4,224 $ 3,386