Note 12 - Employee Benefit Plan (Details Textual) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018
401(k) Plan [Member]
Defined Contribution Plan Disclosure [Line Items]
Discretionary contributions to defined contribution pension plan	$ 0.1	$ 0.1

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

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