Note 9 - Options and Warrants to Purchase Common Stock (Details) - Summary of the Status of the Options Outstanding (USD $)	3 Months Ended
	Mar. 31, 2015
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Number (in Shares)	17,453,116
Options Outstanding, Weighted Average Remaining Contractual Life	5 years 262 days
Options Outstanding, Weighted Average Exercise Price	$ 1.01
Options Exercisable, Number (in Shares)	16,319,783
Options Exercisable, Weighted Average Exercise Price	$ 1.02
Exercise Price 1 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Number (in Shares)	200,000
Options Outstanding, Weighted Average Remaining Contractual Life	9 years 321 days
Options Outstanding, Weighted Average Exercise Price	$ 0.66
Options Exercisable, Number (in Shares)	50,000
Options Exercisable, Weighted Average Exercise Price	$ 0.66
Exercise Price 2 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Number (in Shares)	200,000
Options Outstanding, Weighted Average Remaining Contractual Life	9 years 321 days
Options Outstanding, Weighted Average Exercise Price	$ 0.68
Options Exercisable, Weighted Average Exercise Price	$ 0.68
Exercise Price 3 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Number (in Shares)	7,358,277
Options Outstanding, Weighted Average Remaining Contractual Life	3 years 251 days
Options Outstanding, Weighted Average Exercise Price	$ 0.70
Options Exercisable, Number (in Shares)	7,358,277
Options Exercisable, Weighted Average Exercise Price	$ 0.70
Exercise Price 4 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Number (in Shares)	3,405,134
Options Outstanding, Weighted Average Remaining Contractual Life	6 years 160 days
Options Outstanding, Weighted Average Exercise Price	$ 0.83
Options Exercisable, Number (in Shares)	3,405,134
Options Exercisable, Weighted Average Exercise Price	$ 0.83
Exercise Price 5 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Number (in Shares)	975,000
Options Outstanding, Weighted Average Remaining Contractual Life	9 years 73 days
Options Outstanding, Weighted Average Exercise Price	$ 0.84
Options Exercisable, Number (in Shares)	541,667
Options Exercisable, Weighted Average Exercise Price	$ 0.84
Exercise Price 6 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Number (in Shares)	60,000
Options Outstanding, Weighted Average Remaining Contractual Life	1 year 3 months
Options Outstanding, Weighted Average Exercise Price	$ 1.00
Options Exercisable, Number (in Shares)	60,000
Options Exercisable, Weighted Average Exercise Price	$ 1.00
Exercise Price 7 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Number (in Shares)	300,000
Options Outstanding, Weighted Average Remaining Contractual Life	8 years 142 days
Options Outstanding, Weighted Average Exercise Price	$ 1.10
Options Exercisable, Number (in Shares)	100,000
Options Exercisable, Weighted Average Exercise Price	$ 1.10
Exercise Price 8 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Number (in Shares)	300,000
Options Outstanding, Weighted Average Remaining Contractual Life	8 years 87 days
Options Outstanding, Weighted Average Exercise Price	$ 1.15
Options Exercisable, Number (in Shares)	158,333
Options Exercisable, Weighted Average Exercise Price	$ 1.15
Exercise Price 9 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Number (in Shares)	100,000
Options Outstanding, Weighted Average Remaining Contractual Life	2 years 306 days
Options Outstanding, Weighted Average Exercise Price	$ 1.24
Options Exercisable, Number (in Shares)	100,000
Options Exercisable, Weighted Average Exercise Price	$ 1.24
Exercise Price 10 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Number (in Shares)	115,000
Options Outstanding, Weighted Average Remaining Contractual Life	5 years 361 days
Options Outstanding, Weighted Average Exercise Price	$ 1.35
Options Exercisable, Number (in Shares)	115,000
Options Exercisable, Weighted Average Exercise Price	$ 1.35
Exercise Price 11 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Number (in Shares)	125,000
Options Outstanding, Weighted Average Remaining Contractual Life	2 years 306 days
Options Outstanding, Weighted Average Exercise Price	$ 1.45
Options Exercisable, Number (in Shares)	125,000
Options Exercisable, Weighted Average Exercise Price	$ 1.45
Exercise Price 12 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Number (in Shares)	330,000
Options Outstanding, Weighted Average Remaining Contractual Life	6 years 255 days
Options Outstanding, Weighted Average Exercise Price	$ 1.55
Options Exercisable, Number (in Shares)	321,667
Options Exercisable, Weighted Average Exercise Price	$ 1.55
Exercise Price 13 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Number (in Shares)	7,645
Options Outstanding, Weighted Average Remaining Contractual Life	2 years 306 days
Options Outstanding, Weighted Average Exercise Price	$ 1.58
Options Exercisable, Number (in Shares)	7,645
Options Exercisable, Weighted Average Exercise Price	$ 1.58
Exercise Price 14 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Number (in Shares)	3,077,060
Options Outstanding, Weighted Average Remaining Contractual Life	7 years 237 days
Options Outstanding, Weighted Average Exercise Price	$ 1.66
Options Exercisable, Number (in Shares)	3,077,060
Options Exercisable, Weighted Average Exercise Price	$ 1.66
Exercise Price 15 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Number (in Shares)	900,000
Options Outstanding, Weighted Average Remaining Contractual Life	6 years 142 days
Options Outstanding, Weighted Average Exercise Price	$ 1.90
Options Exercisable, Number (in Shares)	900,000
Options Exercisable, Weighted Average Exercise Price	$ 1.90