Note 11 - Stock-based Compensation (Tables)

9 Months Ended

Sep. 30, 2020

Notes Tables

Share-based Payment Arrangement, Cost by Plan [Table Text Block]

	Three Months Ended September 30,				Nine Months Ended September 30,
	2020		2019		2020			2019
Restricted stock
Research and development	$	142	$	68	$	353		$	129
Selling, general and administrative		500		236		1,122			581
Stock appreciation rights
Research and development		16		132		(61	)		114
Selling, general and administrative		16		132		(67	)		114
Total stock-based compensation	$	674	$	568	$	1,347		$	938

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

						Weighted-
						Average
				Weighted-		Remaining
				Average		Contractual		Aggregate
	Number of			Exercise		Term		Intrinsic
	Options			Price (1)		(years)		Value
Options outstanding at December 31, 2019		1,561		$	928.79		6.56	$	—
Granted		—		$	—
Canceled or forfeited		(9	)	$	72,891.04
Exercised		—		$	—
Options outstanding at September 30, 2020		1,552		$	556.13		5.83	$	—
Options exercisable at September 30, 2020		1,552		$	556.13		5.83	$	—
Options vested and expected to vest at September 30, 2020		1,552		$	556.13		5.83	$	—

Schedule of Nonvested Share Activity [Table Text Block]

				Weighted-
				Average
	Number of			Grant-Date
	Shares			Fair Value
Non-vested at December 31, 2019		1,308,613		$	1.91
Granted		4,454,046		$	0.63
Vested		(1,015,336	)	$	1.47
Canceled or forfeited		(6,974	)	$	1.90
Non-vested at September 30, 2020		4,740,349		$	0.80