Revenue Recognition (Details) - Disaggregation of revenue from contracts with customers - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Digital product sales:
Revenue from contracts with customers	$ 9,445,000	$ 17,035,000
Digital Product Sales [Member]
Digital product sales:
Revenue from contracts with customers	7,378,000	14,710,000
Digital Product Lease And Maintenance [Member]
Digital product sales:
Revenue from contracts with customers	2,067,000	2,325,000
Catalog And Small Customized Products [Member] | Digital Product Sales [Member]
Digital product sales:
Revenue from contracts with customers	6,823,000	13,322,000
Large Customized Products [Member] | Digital Product Sales [Member]
Digital product sales:
Revenue from contracts with customers	555,000	1,388,000
Operating Leases [Member] | Digital Product Lease And Maintenance [Member]
Digital product sales:
Revenue from contracts with customers	936,000	1,215,000
Maintenance Agreements [Member] | Digital Product Lease And Maintenance [Member]
Digital product sales:
Revenue from contracts with customers	$ 1,131,000	$ 1,110,000