Note 1 - Background and Significant Accounting Policies - Earnings (Loss) Per Share (Details) - USD ($)	3 Months Ended		9 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018
Net income from continuing operations available to common stockholders	$ 1,704,803	$ (3,461,810)	$ (3,007,121)	$ (17,308,482)
Interest expense on convertible notes payable	51,608
Effect of assumed conversions	51,608
Income from continuing operations plus assumed conversions	1,756,411	(3,461,810)	(3,007,121)	(17,308,482)
Net loss from discontinued operations available to common stockholders	(360,329)	(301,431)	(738,113)	(1,361,747)
Net income available to common stockholders	$ 1,396,082	$ (3,763,241)	$ (3,745,234)	$ (18,670,229)
Weighted-average common shares outstanding (in shares)	263,055,254	222,856,453	253,297,660	200,971,724
Warrants (in shares)	26,648,530
Convertible notes payable (in shares)	36,086,770
Dilutive potential common shares (in shares)	62,735,300
Adjusted weighted-average shares (in shares)	325,790,554	222,856,453	253,297,660	200,971,724
Net income from continuing operations per common share diluted (in dollars per share)	$ 0.01	$ (0.02)	$ (0.01)	$ (0.08)
Net loss from discontinued operations per common share diluted (in dollars per share)				(0.01)
Net loss per common share diluted (in dollars per share)		$ (0.02)	$ (0.01)	$ (0.09)