Related Party Transactions (Details) (USD $)
3 Months Ended
Mar. 31, 2014
Mar. 31, 2013
Dec. 31, 2013
Related Party Transactions      
Revenue from product sales $ 868,000 $ 1,088,000  
Accounts receivable 600,000   600,000
Investors | Company 1
     
Related Party Transactions      
Revenue from product sales 707,000 558,000  
Investors | Company 2
     
Related Party Transactions      
Revenue from product sales 161,000 126,000  
Investors | Company 3
     
Related Party Transactions      
Revenue from product sales   285,000  
Investors | Company 4
     
Related Party Transactions      
Revenue from product sales   $ 119,000