Description of Business and Summary of Significant Accounting Policies (Concentration) (Details)
$ in Thousands
3 Months Ended 6 Months Ended
Jun. 30, 2016
USD ($)
Jun. 30, 2015
USD ($)
Jun. 30, 2016
USD ($)
item
Jun. 30, 2015
USD ($)
Revenue from U.S., Canadian and all other international dealers and distributors combined        
Total revenue $ 53,215 $ 44,641 $ 96,250 $ 76,724
International revenue (excluding Canada) as a percent of total revenue 22.00% 23.00% 21.00% 24.00%
Segment Reporting        
Number of operating segments | item     1  
United States        
Revenue from U.S., Canadian and all other international dealers and distributors combined        
Total revenue $ 37,461 $ 30,054 $ 68,836 $ 51,271
Canada        
Revenue from U.S., Canadian and all other international dealers and distributors combined        
Total revenue 4,164 4,122 7,109 7,208
All other international sources        
Revenue from U.S., Canadian and all other international dealers and distributors combined        
Total revenue $ 11,590 $ 10,465 $ 20,305 $ 18,245