Commitments and Contingencies (Details) (USD $)
3 Months Ended 9 Months Ended
Sep. 30, 2013
Sep. 30, 2012
Sep. 30, 2013
Sep. 30, 2012
Operating Leases        
Rental expense $ 300,000 $ 300,000 $ 1,000,000 $ 700,000
Future minimum rental payments        
2013 370,000   370,000  
2014 1,452,000   1,452,000  
2015 1,451,000   1,451,000  
2016 1,312,000   1,312,000  
2017 1,124,000   1,124,000  
Thereafter 557,000   557,000  
Total 6,266,000   6,266,000  
Purchase Commitments        
Non-cancellable purchase commitments $ 23,900,000   $ 23,900,000  
Minimum
       
Operating Leases        
Extension term of leases     3 years  
Maximum
       
Operating Leases        
Extension term of leases     5 years