Revenue Recognition (Details) - Disaggregation of revenue from contracts with customers - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Digital product sales:
Revenue from contracts with customers	$ 4,472	$ 3,450	$ 11,818	$ 11,047
Digital Product Sales [Member]
Digital product sales:
Revenue from contracts with customers	3,951	2,857	10,155	9,158
Digital Product Lease And Maintenance [Member]
Digital product sales:
Revenue from contracts with customers	521	593	1,663	1,889
Catalog And Small Customized Products [Member] | Digital Product Sales [Member]
Digital product sales:
Revenue from contracts with customers	3,951	2,857	10,155	8,158
Large Customized Products [Member] | Digital Product Sales [Member]
Digital product sales:
Revenue from contracts with customers				1,000
Operating Leases [Member] | Digital Product Lease And Maintenance [Member]
Digital product sales:
Revenue from contracts with customers	270	350	900	1,116
Maintenance Agreements [Member] | Digital Product Lease And Maintenance [Member]
Digital product sales:
Revenue from contracts with customers	$ 251	$ 243	$ 763	$ 773