Note 11 - Stock-based Compensation (Tables)

3 Months Ended

Mar. 31, 2020

Notes Tables

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

	Three Months Ended March 31,
	2020			2019
Restricted stock
Research and development	$	76		$	28
Selling, general and administrative		260			206
Stock appreciation rights
Research and development		(79	)		16
Selling, general and administrative		(85	)		13
Total stock-based compensation	$	172		$	263

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		—	$	—
Exercised		—	$	—
Options outstanding at March 31, 2020		1,561	$	928.79		6.31	$	—
Options exercisable at March 31, 2020		1,561	$	928.79		6.31	$	—
Options vested and expected to vest at March 31, 2020		1,561	$	928.79		6.31	$	—

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		110,595		$	1.51
Vested		(19,153	)	$	1.87
Canceled or forfeited		(6,974	)	$	1.90
Non-vested at March 31, 2020		1,393,081		$	1.83