Note 7 - Fair Value Measurements (Details Textual) - USD ($)	3 Months Ended	12 Months Ended
Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019	Mar. 05, 2020
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)	362,500
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)	$ 6.75			$ 0.01
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Period Increase (Decrease), Total			$ 865,000
Unamortized Debt Issuance Expense	$ 1,100
Fair Value Adjustment of Warrants	$ 561,000

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

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21475-112644

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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.

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Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.17)
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Amount of expense (income) related to adjustment to fair value of warrant liability.

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