Note 1 - Organization and Capitalization (Details Textual) - USD ($)	Jun. 30, 2021	May 19, 2021	Dec. 31, 2020
Common Stock, Par or Stated Value Per Share (in dollars per share)	$ 0.001		$ 0.001
The 2021 ATM Offering [Member]
Stock Offering Agreement, Maximum Share Value		$ 100,000,000
Common Stock, Par or Stated Value Per Share (in dollars per share)		$ 0.001

Face amount or stated value per share of common stock.

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=120391452&loc=d3e13212-122682

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Balance Type:	na
Period Type:	instant