Note 14 - Weighted Average Shares Outstanding and Net Income (Loss) Per Share - Reconciliation of the Weighted Average Shares Outstanding (Details) (Parentheticals)	Sep. 30, 2021	Dec. 31, 2020	Sep. 30, 2020	Nov. 30, 2019
The 2.75% Convertible Notes [Member]
Interest rate	2.75%	2.75%	2.75%	2.75%

Contractual interest rate for funds borrowed, under the debt agreement.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1B
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495323-112611

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

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