Inventories (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Inventory, Net, Items Net of Reserve Alternative [Abstract]
Finished goods	$ 11,630	$ 8,320
Component parts	7,370	6,768
Service parts	4,339	4,238
Inventories-net	23,339	19,326
Inventory reserves	$ 11,400	$ 9,800