Commitments and Contingencies (Details) - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended
Jun. 30, 2015
Jun. 30, 2014
Jun. 30, 2015
Jun. 30, 2014
Operating Leases        
Rental expense $ 500 $ 400 $ 900 $ 800
Future minimum rental payments        
2015 1,005   1,005  
2016 1,887   1,887  
2017 1,655   1,655  
2018 766   766  
Total 5,313   5,313  
Purchase Commitments        
Non-cancellable purchase commitments $ 28,100   $ 28,100  
Minimum        
Operating Leases        
Extension term of leases     3 years  
Maximum        
Operating Leases        
Extension term of leases     5 years