Related Party Transactions (Details) (USD $)
3 Months Ended 9 Months Ended
Sep. 30, 2013
Sep. 30, 2012
Sep. 30, 2013
Sep. 30, 2012
Dec. 31, 2012
Related Party Transactions          
Revenue from product sales $ 960,000 $ 1,698,000 $ 3,358,000 $ 4,303,000  
Accounts receivable 800,000   800,000   1,500,000
Investors | Company 1
         
Related Party Transactions          
Revenue from product sales 694,000 747,000 2,059,000 1,567,000  
Investors | Company 2
         
Related Party Transactions          
Revenue from product sales   211,000 128,000 813,000  
Investors | Company 3
         
Related Party Transactions          
Revenue from product sales 262,000 372,000 748,000 1,139,000  
Investors | Company 4
         
Related Party Transactions          
Revenue from product sales $ 4,000 $ 368,000 $ 423,000 $ 784,000