Revenue, Major Customer [Line Items]

We currently buy a majority of our integrated circuit board assemblies from three suppliers. Management believes that other suppliers could provide similar products, but a change in suppliers, disputes with our suppliers, or unexpected constraints on the suppliers' production capacity could adversely affect operating results.

Revenue, Major Customer [Line Items]

Segment Information Narrative (Details)	3 Months Ended		6 Months Ended
Segment Information Narrative (Details)	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Revenue, Major Customer [Line Items]
Number of reportable segments			3
Concentration risk, supplier			We currently buy a majority of our integrated circuit board assemblies from three suppliers. Management believes that other suppliers could provide similar products, but a change in suppliers, disputes with our suppliers, or unexpected constraints on the suppliers' production capacity could adversely affect operating results.
Sales [Member] \| Customer A [Member]
Revenue, Major Customer [Line Items]
Concentration Risk, Percentage	13.00%	11.00%	12.00%	11.00%