Accrued Expenses and Other Current Liabilities - Product Warranty Liability (Details) - USD ($)
$ in Thousands
3 Months Ended 9 Months Ended
Sep. 30, 2016
Sep. 30, 2015
Sep. 30, 2016
Sep. 30, 2015
Sep. 30, 2016
Dec. 31, 2015
Movement in Standard and Extended Product Warranty, Increase (Decrease) [Roll Forward]            
Balance at the beginning of the period $ 4,294 $ 3,167 $ 4,152 $ 2,614    
Warranty expense 1,149 1,579 3,288 3,300    
Warranty claims settled (1,101) (992) (3,098) (2,160)    
Balance at the end of the period 4,342 3,754 4,342 3,754    
Composition of balance:            
Short-term         $ 1,640 $ 1,592
Long-term         2,702 2,560
Total warranty balance $ 4,294 $ 3,167 $ 4,152 $ 2,614 $ 4,342 $ 4,152