Note 11 - Stock Based Compensation (Tables)

12 Months Ended

Dec. 31, 2016

Notes Tables

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

Stock Options	Number Outstanding			Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (years)		Aggregate Intrinsic Value
Outstanding at January 1, 2015		1,744,755		$	7.20
Granted		839,250			2.35
Canceled or expired		(444,183	)		5.56
Outstanding at December 31, 2015		2,139,822		$	5.64
Granted		846,283			1.29
Canceled or expired		(53,442	)		9.71
Outstanding at December 31, 2016		2,932,663			4.31		7.2	$	-
Exercisable at December 31, 2016		2,198,907		$	5.09		6.9	$	-

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

Restricted Stock	Number Outstanding			Weighted Average Exercise Price
Non-vested stock awards outstanding at January 1, 2015		7,018		$	3.32
Granted		88,500			2.60
Vested and issued		(14,000	)		2.72
Non-vested stock awards outstanding at December 31, 2015		81,518		$	2.64
Granted		112,000			1.63
Vested and issued		(126,518	)		1.72
Non-vested stock awards outstanding at December 31, 2016		67,000	*	$	2.67

Schedule of Share-based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range [Table Text Block]

			Options Outstanding						Options Exercisable
Range of  Exercise Prices			Number		Weighted Average Remaining Contractual Term (in years)		Weighted Average Exercise Price		Number		Weighted Average Remaining Contractual Term (in years)		Weighted Average Exercise Price
$1.00	to	2.99		1,560,699		8.9	$	1.77		857,897		8.9	$	1.78
3.00	to	5.99		890,857		7.2	$	3.81		859,903		7.2	$	3.69
6.00	to	12.99		322,387		3.0	$	10.82		322,387		3.0	$	10.82
13.00	to	19.99		88,856		3.4	$	14.19		88,856		3.4	$	14.19
Above $20.00				69,864		1.2	$	24.85		69,864		1.2	$	24.85
				2,932,663						2,198,907

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

	Year Ended December 31,
	201 6					201 5
Risk-free interest rate		1.55	to	1.87	%		1.57	to	2.93	%
Expected volatility		87.5	-	89.1	%		92.9	-	104.1	%
Expected life (in years)				10					10
Expected forfeiture rate				5	%				5	%
Expected dividend yield				0.0	%				0.0	%