Note 10 - Sales of Unregistered Securities (Details Textual) - USD ($)		9 Months Ended	12 Months Ended
Dec. 24, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Common Stock, Shares, Issued, Total	5,333,332	6,825,183		4,845,697	38,218,660
Sale of Stock, Price Per Share	$ 0.75
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right	0.5
Class of Warrant or Right, Number of Securities Called by Warrants or Rights	2,666,666
Class of Warrant or Right, Exercise Price of Warrants or Rights	$ 0.75	$ 6.36		$ 6.75
Proceeds from Issuance of Common Stock and Warrants	$ 3,800,000	$ 9,260,000		$ 3,800,000
Payments of Stock Issuance Costs	$ 200,000			$ 200,000

The cash inflow from the additional capital contribution to the entity from issuance of common stock and warrants.

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- Definition

Exercise price per share or per unit of warrants or rights outstanding.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(i)(4))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

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- Definition

Number of securities into which each warrant or right may be converted. For example, but not limited to, each warrant may be converted into two shares.

+ References

No definition available.

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- Definition

Number of securities into which the class of warrant or right may be converted. For example, but not limited to, 500,000 warrants may be converted into 1,000,000 shares.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
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-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

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- Definition

Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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- Definition

The cash outflow for cost incurred directly with the issuance of an equity security.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3291-108585

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- Definition

Per share amount received by subsidiary or equity investee for each share of common stock issued or sold in the stock transaction.

+ References

No definition available.

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