Note 8 - Concentration of Credit Risk (Details Textual) - Customer Concentration Risk [Member]	3 Months Ended
Mar. 31, 2022 USD ($)	Mar. 31, 2021 USD ($)
Revenue Benchmark [Member]
Number of Major Customers	2	2
Revenue Benchmark [Member] \| Customer One [Member]
Concentration Risk, Percentage	43.00%	60.00%
Revenue Benchmark [Member] \| Customer Two [Member]
Concentration Risk, Percentage	23.00%	19.00%
Accounts Receivable [Member] \| Customer One [Member]
Accounts Receivable, before Allowance for Credit Loss	$ 696,000	$ 2,426,000
Concentration Risk, Percentage	20.00%	51.00%
Accounts Receivable [Member] \| Customer Two [Member]
Accounts Receivable, before Allowance for Credit Loss	$ 1,669,000	$ 1,554,000
Concentration Risk, Percentage	48.00%	33.00%

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 42
-URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e9054-108599

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 18
-URI https://asc.fasb.org/extlink&oid=99393423&loc=d3e6351-108592

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 20
-URI https://asc.fasb.org/extlink&oid=123594938&loc=d3e13531-108611

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 21
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=123594938&loc=d3e13537-108611

Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 20
-URI https://asc.fasb.org/extlink&oid=99393423&loc=d3e6404-108592

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