Condensed Consolidated Statements of Stockholders' Equity - USD ($)		Total	Common Stock	Additional Paid-in Capital	Accumulated Deficit
Beginning Balance (in shares) at Dec. 31, 2016			48,106,827
Beginning Balance at Dec. 31, 2016		$ 400,482,639	$ 481,069	$ 783,369,698	$ (383,368,128)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income/(loss)		(27,212,260)			(27,212,260)
Issuance of shares (in shares)			22,222,223
Issuance of shares		96,030,003	$ 222,222	95,807,781
Vesting of restricted shares, net of shares withheld for employee tax (in shares)			1,094
Vesting of restricted shares, net of shares withheld for employee tax		0	$ 11	(11)
Stock-based compensation		6,998,960		6,998,960
Ending Balance (in shares) at Sep. 30, 2017			70,330,144
Ending Balance at Sep. 30, 2017		476,299,342	$ 703,302	886,176,428	(410,580,388)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of accounting change	[1]	(787,110)			(787,110)
Beginning Balance (in shares) at Dec. 31, 2017			70,394,307
Beginning Balance at Dec. 31, 2017		461,165,033	$ 703,944	887,625,902	(427,164,813)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income/(loss)		6,088,334			6,088,334
Issuance of shares (in shares)			530,302
Issuance of shares		0	$ 5,293	(5,293)
Cash received due to exercise of stock options		4,866	$ 10	4,856
Cash used to settle net share equity awards		(2,018,195)		(2,018,195)
Stock-based compensation		8,020,566		8,020,566
Ending Balance (in shares) at Sep. 30, 2018			70,924,609
Ending Balance at Sep. 30, 2018		$ 472,473,494	$ 709,247	$ 893,627,836	$ (421,863,589)

[1] The opening accumulated deficit has been adjusted on January 1, 2018 in connection with adoption of Accounting Standards Update 2014-09 ("ASC 606"). Please refer to Note 2 "Recent Accounting Pronouncements" to the condensed consolidated financial statements.