Note 12 - Stock-based Compensation - Changes in the Number and Weighted-Average Grant-Date Fair Value (Details) shares in Thousands	12 Months Ended
	Dec. 31, 2021 $ / shares shares
Non-vested stock option awards (in shares) | shares	16,020
Weighted average grant-date fair value (in dollars per share) | $ / shares	$ 4.25
Stock option awards granted (in shares) | shares	7,756
Stock option awards granted (in dollars per share) | $ / shares	$ 3.31
Stock option awards vested (in shares) | shares	(5,837)
Stock option awards vested (in dollars per share) | $ / shares	$ 3.97
Stock option awards forfeited (in shares) | shares	(407)
Stock option awards forfeited (in dollars per share) | $ / shares	$ 4.14
Non-vested stock option awards (in shares) | shares	17,532
Weighted average grant-date fair value (in dollars per share) | $ / shares	$ 3.86