Note 11 - Stock-based Compensation (Tables)

6 Months Ended

Jun. 30, 2020

Notes Tables

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

	Three Months Ended June 30,					Six Months Ended June 30,
	2020		2019			2020			2019
Restricted stock
Research and development	$	135	$	33		$	211		$	61
Selling, general and administrative		362		139			622			345
Stock appreciation rights
Research and development		2		(34	)		(77	)		(18	)
Selling, general and administrative		2		(31	)		(83	)		(18	)
Total stock-based compensation	$	501	$	107		$	673		$	370

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

						Weighted-
						Average
				Weighted-		Remaining
				Average		Contractual		Aggregate
	Number of			Exercise		Term		Intrinsic
	Options			Price		(years)		Value
Options outstanding at December 31, 2019		1,561		$	928.79		6.56	$	—
Granted		—		$	—
Canceled or forfeited		(5	)	$	166.44
Exercised		—		$	—
Options outstanding at June 30, 2020		1,556		$	877.93		6.05	$	—
Options exercisable at June 30, 2020		1,556		$	877.93		6.05	$	—
Options vested and expected to vest at June 30, 2020		1,556		$	877.93		6.05	$	—

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		349,750		$	0.98
Vested		(900,180	)	$	1.60
Canceled or forfeited		(6,974	)	$	1.90
Non-vested at June 30, 2020		751,209		$	1.81