Note 9 - Stockholders' Equity (Tables)

12 Months Ended

Dec. 31, 2019

Notes Tables

Fair Value Measurement Inputs and Valuation Techniques [Table Text Block]

Expected term (years)	7
Expected volatility	55	%
Risk-free interest rate	2	%
Dividend rate	—

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

	Number of Shares			Weighted Average Exercise Price		Weighted Average Remaining Contractual Life (in years)		Intri n sic Value
Balance at December 31, 2017		7,663		$	2,917.30			$	—
Options granted		3,100		$	16.70
Options expired		(2,550	)	$	2,725.80
Options forfeited		(259	)	$	3,493.70
Balance at December 31, 2018		7,954		$	1,707.30			$	—
Options expired		(448	)	$	3,061.09
Options forfeited		(105	)	$	1,929.52
Balance at December 31, 2019		7,401		$	1,309.47		6.81	$	—
Exercisable at December 31, 2019		7,224		$	1,310.25		6.80	$	—
Vested and expected to vest at December 31, 2019		7,401		$	1,309.47		6.81	$	—

Share-based Payment Arrangement, Option, Exercise Price Range [Table Text Block]

Options Outstanding								Options Vested
				Weighted		Weighted				Weighted
				Average		Average				Average
Exercise		Options		Remaining		Exercise		Number		Exercise
Price		Outstanding		Contractual Life		Price		Exercisable		Price
$	16.70		3,100		8.44	$	16.70		3,100	$	16.70
$	204.00		5		7.56	$	204.00		3	$	204.00
$	820.00		1,001		7.21	$	820.00		856	$	820.00
$	1,052.00		46		7.18	$	1,052.00		36	$	1,052.00
$	1,420.00		70		6.84	$	1,420.00		70	$	1,420.00
$	1,472.00		10		6.83	$	1,472.00		8	$	1,472.00
$	1,800.00		2,440		5.00	$	1,800.00		2,440	$	1,800.00
$	1,980.00		28		0.32	$	1,980.00		28	$	1,980.00
$	4,364.00		10		5.18	$	1,980.00		10	$	1,980.00
$	4,404.00		25		6.43	$	4,404.00		25	$	4,404.00
$	4,952.00		18		6.33	$	4,952.00		18	$	4,952.00
$	5,040.00		24		1.47	$	5,040.00		24	$	5,040.00
$	5,184.00		151		6.19	$	5,184.00		141	$	5,184.00
$	5,196.00		241		6.18	$	5,196.00		233	$	5,196.00
$	5,940.00		14		2.02	$	5,940.00		14	$	5,940.00
$	6,084.00		11		5.58	$	6,084.00		11	$	6,084.00
$	7,290.00		3		4.04	$	7,290.00		3	$	7,290.00
$	7,844.00		110		5.91	$	7,844.00		110	$	7,844.00
$	8,100.00		94		3.73	$	8,100.00		94	$	8,100.00
			7,401		6.81	$	1,309.47		7,224	$	1,310.25

Share-based Payment Arrangement, Restricted Stock Unit, Activity [Table Text Block]

	Number of Shares			Weighted Average Grant Date Fair Value		Weighted Average Remaining Contractual Term
Awards outstanding at December 31, 2017		509		$	2,377.80		2.87
Awarded		297,753		$	15.00
Released		(128	)	$	2,739.70
Forfeited		(4,068	)	$	59.70
Awards outstanding at December 31, 2018		294,066		$	17.34		3.09
Awarded		764,151		$	1.24
Released		(101,575	)	$	17.95
Forfeited		(48,138	)	$	10.57
Awards outstanding at December 31, 2019		908,504		$	4.09		1.81