Note 15 - Stock Options and Stock-based Employee Compensation (Tables)

12 Months Ended

Dec. 31, 2019

Notes Tables

Schedule of Share Based Compensation Arrangement by Stock Options and Restricted Stock Units Outstanding and Available for Future Issuance [Table Text Block]

	December 31,
(in thousands)	2019		2018
Stock Options and RSUs Outstanding
2011 Plan		1,804		1,519
Non-Plan		3		3
Total Outstanding		1,807		1,522
Available for Future Grants under 2011 Plan		149		484

Disclosure of Share-based Compensation Arrangements by Share-based Payment Award [Table Text Block]

(in thousands, except for weighted-average data) Stock Options	Shares			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (In Yrs)
Outstanding at January 1, 2019		1,472		$	20.19
Granted		382			9.99
Forfeited or expired		(82	)		40.74
Outstanding at December 31, 2019		1,772		$	17.61		9.0
Vested and exercisable at December 31, 2019		521		$	29.34		8.9
Vested and expected to vest at December 31, 2019		1,692		$	17.55		9.0

Schedule of Nonvested Restricted Stock Units Activity [Table Text Block]

(in thousands, except for weighted-average data)
Restricted Stock Units	Shares			Weighted- Average Grant Date Fair Value
Unvested at January 1, 2019		50		$	12.87
Awarded		83			11.85
Cancelled		(48	)		12.99
Vested		(50	)		12.87
Unvested at December 31, 2019		35		$	11.85

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

	Year Ended December 31,
(in thousands)	2019		2018
Research and development	$	1,932	$	232
Selling, general and administrative		4,789		723
Total	$	6,721	$	955

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]

	Year Ended December 31,
	2019			2018
Weighted average expected volatility		95	%		93	%
Weighted average expected term (years)		6.6			7.0
Weighted average risk-free interest rate		2.6	%		2.7	%
Expected dividends		-			-