Revenue Recognition (Details) - Disaggregation of revenue from contracts with customers - USD ($)	3 Months Ended
Mar. 31, 2021	Mar. 31, 2020
Digital product sales:
Revenue from contracts with customers	$ 2,586,000	$ 1,913,000
Digital Product Sales [Member]
Digital product sales:
Revenue from contracts with customers	2,093,000	1,334,000
Digital Product Lease And Maintenance [Member]
Digital product sales:
Revenue from contracts with customers	493,000	579,000
Catalog And Small Customized Products [Member] \| Digital Product Sales [Member]
Digital product sales:
Revenue from contracts with customers	2,093,000	1,334,000
Large Customized Products [Member] \| Digital Product Sales [Member]
Digital product sales:
Revenue from contracts with customers
Operating Leases [Member] \| Digital Product Lease And Maintenance [Member]
Digital product sales:
Revenue from contracts with customers	209,000	279,000
Maintenance Agreements [Member] \| Digital Product Lease And Maintenance [Member]
Digital product sales:
Revenue from contracts with customers	$ 284,000	$ 300,000

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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+ Details