Note 2 - Summary of Significant Accounting Policies - Credit Concentration (Details) - Customer Concentration Risk [Member]	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018
Customer A [Member] \| Revenue from Contract with Customer Benchmark [Member]
Credit concentration	10.00%	33.00%
Customer B [Member] \| Accounts Receivable [Member]
Credit concentration	10.00%	12.00%
Customer C [Member] \| Accounts Receivable [Member]
Credit concentration	10.00%	31.00%
Customer D [Member] \| Accounts Receivable [Member]
Credit concentration	20.00%	10.00%
Customer E [Member] \| Accounts Receivable [Member]
Credit concentration	14.00%	10.00%
Customer F [Member] \| Accounts Receivable [Member]
Credit concentration	13.00%	10.00%

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://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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