Note 7 - Loss Per Share - Shares Used in Basic and Diluted Loss Per Common Share Computations (Details) - USD ($)		3 Months Ended		6 Months Ended
		Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Net gain/(loss) attributable to common shareholder per common share basic and diluted calculation		$ 1,444,706	$ (2,373,410)	$ (1,848,478)	$ (4,133,432)
Net gain/(loss)		$ 1,444,706	$ (2,373,410)	$ (1,848,478)	$ (4,133,432)
Weighted average shares used in computation - basic (in shares)		29,609,373	11,878,490	22,747,544	11,632,221
Effect of diluted stock options, warrants and preferred stock (1) (in shares)	[1]	30,461,410
Weighted average common shares outstanding-diluted (in shares)		60,070,783	11,878,490	22,747,544	11,632,221
Gain/(loss) per common share - basic (in dollars per share)		$ 0.05	$ (0.20)	$ (0.08)	$ (0.36)
Gain/(loss) per common share – diluted (in dollars per share)		$ 0.02	$ (0.20)	$ (0.08)	$ (0.36)

[1] The number of shares underlying options and warrants outstanding as of June 30, 2019 and June 30, 2018 are 27,559,457 and 5,676,637, respectively. The number of shares underlying the convertible debt as of June 30, 2019 and June 30, 2018 is 1,303,073 and zero, respectively. The number of shares underlying the preferred stock Series C as of June 30, 2019 and June 30, 2018 is 79,246. The number of shares underlying the preferred stock Series D as of June 30, 2019 and June 30, 2018 is 35,000 and zero, respectively. The number of shares underlying the preferred stock Series E as of June 30, 2019 and June 30, 2018 is 1,484,634 and zero, respectively. The effect of the shares that would be issued upon exercise of such options, warrants, convertible debt and preferred stock has been excluded from the calculation of diluted loss per share because those shares are anti-dilutive.