Note 10 - Convertible Preferred Stock and Stockholder's Equity (Details Textual)				1 Months Ended		10 Months Ended	12 Months Ended
	Jan. 22, 2018 shares	Mar. 31, 2017 $ / shares $ / item shares	Jan. 07, 2016 USD ($) shares	Jan. 31, 2018 shares	Mar. 31, 2017 USD ($) $ / shares $ / item shares	Jan. 07, 2018 USD ($)	Dec. 31, 2017 USD ($) $ / shares shares	Dec. 31, 2016 USD ($) shares	Mar. 14, 2017 $ / item
Proceeds from Issuance of Convertible Preferred Stock, Net of Offering Costs | $							$ 22,129,774
Warrant Expense | $							10,225,846
Dividends | $							1,252,394
Stock Reclassified Upon Conversion of Preferred Stock | $							$ 190,080
Make-Whole Provision Conversion Price, Percentage							105.00%
Class of Warrant or Right, Number of Securities Called by Warrants or Rights			478,200
Stock Issued During Period, Shares, Total								2,226,698
Stock Issued During Period, Shares, Acquisitions								1,861,503
Stock Issued During Period, Shares, Issued for Services							17,606	45,643
Stock Issued During Period, Shares, Conversion of Convertible Securities								217,122
Fair Value Adjustment of Warrants | $							$ (22,072,322)
General Financial Advisory Services [Member]
Stock Issued During Period, Shares, Issued for Services								102,430
Diffusion LLC [Member]
Noncash or Part Noncash Divestiture, Amount of Consideration Received | $			$ 400,000
Maximum [Member]
Convertible Preferred Stock, Conversion Price							2.02
Minimum [Member]
Financing Trigger from Issuance of Common Stock | $							$ 10,000,000
Convertible Preferred Stock, Make-Whole Provision, Proceeds from Issue of Common Stock | $							10,000,000
Subsequent Event [Member]
Stock Issued During Period, Shares, Make-whole Adjustment				11,668,421
Conversion From Series A Preferred Stock to Common Stock [Member] | Subsequent Event [Member]
Conversion of Stock, Shares Issued	20,568,632
Conversion From Series A Preferred Stock to Common Stock Automated Conversion [Member] | Subsequent Event [Member]
Conversion of Stock, Shares Issued	8,306,278
Conversion From Series A Preferred Stock to Common Stock, Settlement of Accrued Dividends [Member] | Subsequent Event [Member]
Conversion of Stock, Shares Issued	593,933
Conversion From Series A Preferred Stock to Common Stock, Make-Whole Adjustment [Member] | Subsequent Event [Member]
Conversion of Stock, Shares Issued	11,668,421
Warrant [Member]
Warrant Expense | $							$ 10,200,000
Class of Warrant or Rights, Expired							13,000	17,479
Private Placement [Member]
Convertible Preferred Stock, Votes Per Share | $ / item		0.50627			0.50627				0.84874
Private Placement [Member] | Warrant [Member]
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right		1			1
Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares		$ 2.22			$ 2.22
Class of Warrant or Right, Term		5 years
Warrant Expense | $							$ 10,200,000
Series A Preferred Stock [Member]
Preferred Stock, Shares Authorized							13,750,000
Proceeds from Issuance of Private Placement | $							$ 0
Dividends | $							$ 1,252,394
Stock Reclassified Upon Conversion of Preferred Stock, Shares							86,335
Stock Reclassified Upon Conversion of Preferred Stock | $							$ 1,100,000
Conversion of Stock, Shares Converted							4,070,051
Fair Value Adjustment of Warrants | $							$ 22,100,000
Series A Preferred Stock [Member] | Maximum [Member]
Convertible Preferred Stock, Make-Whole Provision, Minimum Share Price | $ / shares							$ 8
Series A Preferred Stock [Member] | Conversion From Series A Preferred Stock to Common Stock [Member]
Dividends | $							$ 200,000
Series A Preferred Stock [Member] | Private Placement [Member]
Proceeds from Issuance of Private Placement | $					$ 25,000,000
Number of Convertible Preferred Stock Per Unit		1
Preferred Stock, Dividend Rate, Percentage		8.00%
Number of Common Stock Per Unit		1
Convertible Preferred Stock, Conversion Price		2.02			2.02
Temporary Equity, Stock Issued During Period, New Issues					12,376,329
Proceeds from Issuance of Convertible Preferred Stock, Net of Offering Costs | $					$ 22,100,000
Payments of Stock Issuance Costs | $						$ 2,900,000
Dividends | $							$ 1,300,000
Series B Preferred Stock [Member] | Private Placement [Member] | Placement Agent [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares		$ 2.22			$ 2.22
Class of Warrant or Right, Term		5 years
Class of Warrant or Right, Granted During Period					1,179,558
Series A Convertible Preferred Stock [Member] | Subsequent Event [Member]
Preferred Stock, Dividend Rate, Percentage	8.00%