Description of Business and Summary of Significant Accounting Policies (Concentration) (Details)
$ in Thousands
3 Months Ended 9 Months Ended
Sep. 30, 2016
USD ($)
Sep. 30, 2015
USD ($)
Sep. 30, 2016
USD ($)
item
Sep. 30, 2015
USD ($)
Revenue from U.S., Canadian and all other international dealers and distributors combined        
Total revenue $ 55,185 $ 43,558 $ 151,435 $ 120,282
International revenue (excluding Canada) as a percent of total revenue 20.00% 24.00% 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 $ 39,670 $ 29,300 $ 108,506 $ 80,571
Canada        
Revenue from U.S., Canadian and all other international dealers and distributors combined        
Total revenue 4,246 3,702 11,355 10,910
All other international sources        
Revenue from U.S., Canadian and all other international dealers and distributors combined        
Total revenue $ 11,269 $ 10,556 $ 31,574 $ 28,801