Business Segment Data (Details) - Business Segment Data - USD ($)	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Revenues:
Revenues	$ 2,624,000	$ 4,349,000
Operating (loss) income:
Operating (loss) income	(1,122,000)	(637,000)
Interest expense, net	(142,000)	(144,000)
Gain (loss) on foreign currency remeasurement	52,000	(8,000)
Pension expense	(50,000)	(63,000)
Loss before income taxes	(1,262,000)	(852,000)
Income tax expense	(7,000)	(6,000)
Net loss	(1,269,000)	(858,000)
Assets	7,858,000		$ 8,330,000
Operating Segments [Member]
Operating (loss) income:
Assets	7,762,000		8,145,000
Segment Reporting, Reconciling Item, Corporate Nonsegment [Member]
Operating (loss) income:
Operating (loss) income	(473,000)	(459,000)
Assets	96,000		185,000
Digital Product Sales [Member]
Revenues:
Revenues	2,429,000	4,121,000
Digital Product Sales [Member] | Operating Segments [Member]
Revenues:
Revenues	2,429,000	4,121,000
Operating (loss) income:
Operating (loss) income	(759,000)	(301,000)
Assets	7,164,000		7,502,000
Digital Product Lease and Maintenance [Member]
Revenues:
Revenues	195,000	228,000
Digital Product Lease and Maintenance [Member] | Operating Segments [Member]
Revenues:
Revenues	195,000	228,000
Operating (loss) income:
Operating (loss) income	110,000	$ 123,000
Assets	$ 598,000		$ 643,000