Note 10 - Stockholders' Equity (Tables)

12 Months Ended

Dec. 31, 2018

Notes Tables

Schedule of Stockholders' Equity Note, Warrants or Rights [Table Text Block]

	Year Ended December 31,					Six Months Ended December 31,				Year Ended June 30,
	2018					2017				2017
	Number of Shares			Weighted- Average Exercise Price Per Share		Number of Shares		Weighted- Average Exercise Price Per Share		Number of Shares		Weighted- Average Exercise Price Per Share
Beginning balance		4,828,723		$	9.37		4,828,723	$	9.37		4,828,723	$	9.37
Warrants granted		15,128,151		$	0.42		--				--
Warrants exercised		(2,691,666	)	$	0.01
Warrants expired/canceled		--					--				--
Outstanding		17,265,208		$	2.99		4,828,723	$	9.37		4,828,723	$	9.37
Exercisable		16,566,679		$	2.78		4,130,194	$	9.60		4,130,194	$	9.60

Share-based Compensation, Stock Options, Activity [Table Text Block]

	Number of Shares			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Life		Aggregate Intrinsic Value
Outstanding at January 1, 2018		1,156,027		$	3.92
Granted		2,233,500		$	0.40
Forfeited/cancelled		(338,518	)	$	3.10
Expired		(27,370	)	$	4.83
Exercised		--
Outstanding at December 31, 2018		3,023,639		$	1.40		9.3		--
Vested and Expected to Vest at December 31, 2018		1,893,518		$	1.77		8.9		--
Exercisable at December 31, 2018		901,742		$	2.79		8.1		--

Non Vested Stock Options Activity [Table Text Block]

<div style="display: inline; font-family: times new roman; font-size: 10pt"><table border="0" cellpadding="0" cellspacing="0" style="; font-size: 10pt; font-family: "Times New Roman", Times, serif; text-indent: 0px; min-; min-width: 700px;"> <tr style="vertical-align: bottom;"> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt; width: 62%;"> </td> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt; width: 1%;"> </td> <td colspan="2" style="text-align: center; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt; border-bottom: 1px solid rgb(0, 0, 0); width: 1%;"> <div style=" font-family:'Times New Roman', Times, serif;font-size:10pt;margin:0pt;text-align:center;">Non-vested Stock</div> <div style=" font-family:'Times New Roman', Times, serif;font-size:10pt;margin:0pt;text-align:center;">Options</div> </td> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt; padding-bottom: 1px; width: 1%;"> </td> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt; width: 1%;"> </td> <td colspan="2" style="text-align: center; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt; border-bottom: 1px solid rgb(0, 0, 0); width: 1%;"> <div style=" font-family:'Times New Roman', Times, serif;font-size:10pt;margin:0pt;text-align:center;">Weighted-Average Grant</div> <div style=" font-family:'Times New Roman', Times, serif;font-size:10pt;margin:0pt;text-align:center;">Date Fair Value</div> </td> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt; padding-bottom: 1px; width: 1%;"> </td> </tr> <tr style="vertical-align: bottom; background-color: rgb(204, 238, 255);"> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt; width: 62%;"> <div style=" font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-top: 0pt; margin-bottom: 0pt;">Outstanding at January 1, 2018</div> </td> <td style="width: 1%; border-bottom: 1px none rgb(0, 0, 0); font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="width: 1%; border-bottom: 1px none rgb(0, 0, 0); font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="width: 16%; border-bottom: 1px none rgb(0, 0, 0); text-align: right; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;"><div style="display: inline; font-style: italic; font-weight: inherit; font-style: normal;">835,708</div></td> <td nowrap="nowrap" style="width: 1%; border-bottom: 1px none rgb(0, 0, 0); font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;"> </td> <td style="width: 1%; border-bottom: 1px none rgb(0, 0, 0); font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="width: 1%; border-bottom: 1px none rgb(0, 0, 0); font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;"> </td> <td style="width: 16%; border-bottom: 1px none rgb(0, 0, 0); font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt; text-align: center;"><div style="display: inline; font-style: italic; font-weight: inherit; font-style: normal;">$2.37</div></td> <td nowrap="nowrap" style="width: 1%; border-bottom: 1px none rgb(0, 0, 0); font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;"> </td> </tr> <tr style="vertical-align: bottom; background-color: rgb(255, 255, 255);"> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt; width: 62%;"> <div style=" font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-top: 0pt; margin-bottom: 0pt;">Granted</div> </td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="width: 16%; text-align: right; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;"><div style="display: inline; font-style: italic; font-weight: inherit; font-style: normal;">2,233,500</div></td> <td nowrap="nowrap" style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;"> </td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;"> </td> <td style="width: 16%; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt; text-align: center;"><div style="display: inline; font-style: italic; font-weight: inherit; font-style: normal;">$0.32</div></td> <td nowrap="nowrap" style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;"> </td> </tr> <tr style="vertical-align: bottom; background-color: rgb(204, 238, 255);"> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt; width: 62%;"> <div style=" font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-top: 0pt; margin-bottom: 0pt;">Vested</div> </td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="width: 16%; text-align: right; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;"><div style="display: inline; font-style: italic; font-weight: inherit; font-style: normal;">(651,180</div></td> <td nowrap="nowrap" style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;">)</td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;"> </td> <td style="width: 16%; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt; text-align: center;"><div style="display: inline; font-style: italic; font-weight: inherit; font-style: normal;">$0.97</div></td> <td nowrap="nowrap" style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;"> </td> </tr> <tr style="vertical-align: bottom; background-color: rgb(255, 255, 255);"> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt; width: 62%;"> <div style=" font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-top: 0pt; margin-bottom: 0pt;">Forfeited</div> </td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt; border-bottom: 1px solid rgb(0, 0, 0);"> </td> <td style="width: 16%; text-align: right; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt; border-bottom: 1px solid rgb(0, 0, 0);"><div style="display: inline; font-style: italic; font-weight: inherit; font-style: normal;">(296,131</div></td> <td nowrap="nowrap" style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt; padding-bottom: 1px;">)</td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;"> </td> <td style="width: 16%; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt; text-align: center;"><div style="display: inline; font-style: italic; font-weight: inherit; font-style: normal;">$2.35</div></td> <td nowrap="nowrap" style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt; padding-bottom: 1px; margin-left: 0pt;"> </td> </tr> <tr style="vertical-align: bottom; background-color: rgb(204, 238, 255);"> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt; width: 62%;"> <div style=" font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-top: 0pt; margin-bottom: 0pt;">Outstanding at December 31, 2018</div> </td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt; border-bottom: 3px double rgb(0, 0, 0);"> </td> <td style="width: 16%; text-align: right; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt; border-bottom: 3px double rgb(0, 0, 0);"><div style="display: inline; font-style: italic; font-weight: inherit; font-style: normal;">2,121,897</div></td> <td nowrap="nowrap" style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt; padding-bottom: 3px; margin-left: 0pt;"> </td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;"> </td> <td style="width: 16%; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt; text-align: center;"><div style="display: inline; font-style: italic; font-weight: inherit; font-style: normal;">$0.64</div></td> <td nowrap="nowrap" style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt; padding-bottom: 3px; margin-left: 0pt;"> </td> </tr> </table></div>

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

	Year Ended December 31,		Six Months Ended December 31,		Year Ended June 30,
	2018		2017		2017
Expected life (years)		6		6		4
Risk-free interest rate		2.7%		2.3%		1.3%
Expected volatility		103%		95%		102%
Dividend yield		0%		0%		0%

Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity [Table Text Block]

	Year Ended December 31,					Six Month Ended December 31,					Year Ended June 30,
	2018					2017					2017
	Number of Shares			Weighted -Average Grant Date Fair Value		Number of Shares			Weighted -Average Grant Date Fair Value		Number of Shares			Weighted -Average Grant Date Fair Value
Balance at beginning of period		416			$17.60		59,694			$4.62		63,566			$14.96
Granted		--					10,000			$3.26		123,417			$4.55
Vested		(416	)		$17.60		(69,278	)		$4.35		(125,513	)		$9.47
Forfeited		--					--					(1,776	)		$27.05
Outstanding at end of period		--					416			$17.60		59,694			$4.62