Basis of Preparation (Details) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Current Assets [Abstract]
Investment in sales-type sublease - current	$ 0	$ 1,204,000	$ 532,000
Long-term Assets [Abstract]
Investment in sales-type sublease - net of current portion	0	0
Operating lease right-of-use asset	86,000	120,000	94,000
Total leased assets	86,000	1,324,000
Current Liabilities [Abstract]
Obligations under finance lease - current portion	0	620,000	89,000
Operating lease right-of-use liability - current portion	40,000	37,000	40,000
Long-term Liabilities [Abstract]
Obligations under finance lease - net of current portion	0	0
Operating lease right-of-use liability - net of current portion	56,000	97,000	$ 66,000
Total lease liabilities	96,000	754,000
Lease Cost [Abstract]
Net lease expense	5,000
Net lease income		(2,000)
Operating lease [Abstract]
2021	34,000
2022	46,000
2023	24,000
Total	104,000
Less amount representing interest	8,000
Present value of lease liabilities	$ 96,000
Discount rate	5.85%
Selling, General and Administrative Expenses [Member]
Lease Cost [Abstract]
Operating lease cost	$ 11,000	11,000
Interest Expense [Member]
Lease Cost [Abstract]
Finance lease cost, interest on lease liabilities	2,000	11,000
Interest Income - Sales-type Sublease [Member]
Lease Cost [Abstract]
Sublease income	$ 8,000	$ 24,000