Note 12 - Convertible Senior Notes - Schedule of Carrying Value of Convertible Senior Notes (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020	Mar. 05, 2019
Net carrying amount	$ 78,472	$ 77,854
The 5% Convertible Senior Notes Due 2024 [Member]
Principal	80,500	80,500	$ 80,500
Unamortized debt issuance costs	(2,028)	(2,646)
Net carrying amount	$ 78,472	$ 77,854

Face (par) amount of debt instrument at time of issuance.

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