Note 3 - Basis of Presentation and Summary of Significant Accounting Policies - Basic and Diluted Earnings Per Share (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Net income (loss)	$ 20,387,741	$ (3,806,194)	$ (8,251,037)	$ (10,029,359)
Accretion of Series A cumulative preferred dividends	(487,460)		(546,305)
Undistributed earnings allocated to participating securities	(10,416,153)
Net income (loss) attributable to common stockholders	9,484,128	(3,806,194)	(8,797,342)	(10,029,359)
Net income (loss) attributable to common stockholders	9,484,128	(3,806,194)	(8,797,342)	(10,029,359)
Fair Value Adjustment of Warrants	(23,387,850)		(10,468,176)
Diluted net loss	$ (13,903,722)	$ (3,806,194)	$ (19,265,518)	$ (10,029,359)
Weighted average shares outstanding, basic (in shares)	10,828,063	10,263,703	10,582,521	10,130,042
Net income (loss) per share of common stock, basic (in dollars per share)	$ 0.88	$ (0.37)	$ (0.83)	$ (0.99)
Shares from dilutive warrants	$ 3,044,569		$ 1,756,865
Weighted average shares outstanding, diluted (in shares)	13,872,632	10,263,703	12,339,386	10,130,042
Net income (loss) per share of common stock, diluted (in dollars per share)	$ (1)	$ (0.37)	$ (1.56)	$ (0.99)