Note 1 - Nature of Business and Basis of Presentation (Details Textual) $ in Millions	51 Months Ended
Jun. 30, 2022 USD ($)
Proceeds from Issuance or Sale of Equity	$ 412
Cash and Marketable Securities	$ 169

The cash inflow from the issuance of common stock, preferred stock, treasury stock, stock options, and other types of equity.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 45
-Paragraph 14
-Subparagraph (a)
-SubTopic 10
-Topic 230
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482740/230-10-45-14

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 3
-Subparagraph (SX 210.6-03(i)(1))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479886/946-10-S99-3

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Balance Type:	debit
Period Type:	duration