Amount of cost not yet recognized for nonvested award under share-based payment arrangement.

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Note 8 - Stock-based Compensation (Details Textual) - USD ($) $ / shares in Units, $ in Thousands, shares in Millions			6 Months Ended
	Jun. 30, 2024	Jan. 01, 2024	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2020
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount	$ 19,400		$ 19,400
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value (in dollars per share)			$ 1.82	$ 2.85
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value			$ 0
Share-Based Payment Arrangement, Nonvested Award, Option, Cost Not yet Recognized, Amount	11,400		11,400	$ 11,300
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested and Expected to Vest, Outstanding, Aggregate Intrinsic Value	0		$ 0	$ 600
Share-Based Payment Arrangement, Option [Member]
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition			1 year 6 months	3 years
Restricted Stock Units (RSUs) [Member]
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount	$ 8,000		$ 8,000
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value			$ 884
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition	1 year 9 months 18 days
The 2020 Stock Option and Incentive Plan [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Authorized					2.9
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Additional Shares Authorized		5.1
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant	4.5		4.5
The 2020 Stock Option and Incentive Plan [Member] \| Share-Based Payment Arrangement, Option [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period (Year)			4 years
Share-Based Compensation Arrangement by Share-Based Payment Award, Expiration Period (Year)			10 years