Note 11 - Stock-based Compensation - RSU Activity (Details) - Restricted Stock Units (RSUs) [Member]	6 Months Ended
	Jun. 30, 2022 $ / shares shares
Beginning of period, Restricted stock units, Unvested (in shares) | shares	3,839,030
Beginning of period, Restricted stock units, Unvested, weighted average grant date fair value (in dollars per share) | $ / shares	$ 2.36
Restricted stock units, Granted (in shares) | shares	6,040,915
Restricted stock units, Granted, weighted average grant date fair value (in dollars per share) | $ / shares	$ 0.75
Restricted stock units, Vested (in shares) | shares	(1,794,623)
Restricted stock units, Vested, weighted average grant date fair value (in dollars per share) | $ / shares	$ 2.47
Restricted stock units, Forfeited (in shares) | shares	(100,047)
Restricted stock units, Forfeited, weighted average grant date fair value (in dollars per share) | $ / shares	$ 1.36
Beginning of period, Restricted stock units, Unvested (in shares) | shares	7,985,275
Beginning of period, Restricted stock units, Unvested, weighted average grant date fair value (in dollars per share) | $ / shares	$ 1.13