Note 7 - Stock-based Compensation (Tables)

9 Months Ended

Sep. 30, 2023

Notes Tables

Share-Based Payment Arrangement, Option, Activity [Table Text Block]

	Options Outstanding
	Number of Options			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Life (years)		Aggregate Intrinsic Value
Balance—January 1, 2023		368,596		$	9.26		5.89	$	—
Options granted		—		$	—		—	$	—
Options exercised		—		$	—		—	$	—
Options canceled		(172,292	)	$	9.32		—	$	—
Balance—September 30, 2023		196,304		$	9.21		5.25	$	—
Exercisable as of September 30, 2023		196,304		$	9.21		5.25	$	—
Vested and expected to vest as of September 30, 2023		196,304		$	9.21		5.25	$	—

Nonvested Restricted Stock Shares Activity [Table Text Block]

Restricted Stock Awards	Shares			Weighted Average Grant- Date Fair Value
Nonvested at January 1, 2023		4,223,023		$	4.85
Granted		12,050,644		$	0.52
Vested		(2,666,468	)	$	3.21
Forfeited		(3,970,751	)	$	2.23
Nonvested at September 30, 2023		9,636,448		$	0.96

Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block]

	Three Months Ended September 30,				Nine Months Ended September 30,
	2022		2023		2022		2023
	(in thousands)				(in thousands)
Sales and distribution expenses	$	999	$	330	$	4,228	$	2,091
Research and development expenses		511		278		1,418		1,134
General and administrative expenses		1,433		624		6,208		3,546
Total stock-based compensation expense	$	2,943	$	1,232	$	11,854	$	6,771