Note 11 - Stock-based Compensation - Restricted Stock Awards Activities (Details) - Restricted Stock [Member] shares in Thousands	6 Months Ended
	Jun. 30, 2023 $ / shares shares
Nonvested (in shares) | shares	6,616
Nonvested, grant date fair value (in dollars per share) | $ / shares	$ 0.041
Restricted stock granted (in shares) | shares	4,700
Restricted stock granted, grant date fair value (in dollars per share) | $ / shares	$ 0.033
Vested (in shares) | shares	(2,985)
Vested, grant date fair value (in dollars per share) | $ / shares	$ 0.039
Forfeited (in shares) | shares	(316)
Forfeited (in dollars per share) | $ / shares	$ 0.035
Nonvested (in shares) | shares	8,015
Nonvested, grant date fair value (in dollars per share) | $ / shares	$ 0.034