Note 3 - Basis of Presentation and Summary of Significant Accounting Policies (Tables)

6 Months Ended

Jun. 30, 2017

Notes Tables

Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]

	Three Months Ended June 30,						Six Months Ended June 30,
	2017			2016			2017			2016
Basic net income (loss) per common share calculation:
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	)
Weighted average shares outstanding, basic		10,828,063			10,263,703			10,582,521			10,130,042
Net income (loss) per share of common stock, basic	$	0.88		$	(0.37	)	$	(0.83	)	$	(0.99	)
Diluted net income (loss) per common share calculation:
Net income (loss) attributable to common stockholders	$	9,484,128			(3,806,194	)		(8,797,342	)		(10,029,359	)
Change in fair value of warrant liability		(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		10,828,063			10,263,703			10,582,521			10,130,042
Shares from dilutive warrants		3,044,569			—			1,756,865			—
Weighted average shares outstanding, diluted		13,872,632			10,263,703			12,339,386			10,130,042
Net income (loss) per share of common stock, diluted	$	(1.00	)	$	(0.37	)	$	(1.56	)	$	(0.99	)

Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block]

	June 30,
	2017		2016
Convertible debt		774,886		429,161
Convertible preferred stock		10,449,338		—
Common stock warrants		457,721		461,209
Stock options		2,525,989		1,797,812
Unvested restricted stock awards		6,132		12,273
		14,214,066		2,700,455