CONDENSED STATEMENT OF STOCKHOLDERS' EQUITY (DEFICIT) - USD ($)	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Retained Deficit	Total
Balance at beginning of period at Dec. 31, 2016			$ (41,196)
Net loss					$ (11,488,585)
Unrealized gain (loss) on securities					(12,681)
Balance at end of period at Mar. 31, 2017			(53,877)
Cumulative Effect of New Accounting Principle in Period of Adoption | ASU 2014-09				$ 339,406	339,406
Balance after adjustment	$ 48,204	$ 404,454,909	(64,433)	(308,615,129)	95,823,551
Balance at beginning of period at Dec. 31, 2017	$ 48,204	404,454,909	(64,433)	(308,954,535)	95,484,145
Balances (in shares) at Dec. 31, 2017	48,203,529
Exercise of stock options	$ 561	2,302,412			$ 2,302,973
Exercise of stock options (in shares)	561,088				561,088
Stock-based compensation	$ 127	1,251,211			$ 1,251,338
Stock-based compensation (in shares)	127,442
Issuance of common stock in connection with equity offering	$ 20,536	80,920,845			80,941,381
Issuance of common stock in connection with equity offering (in shares)	20,535,714
Net loss				(8,602,646)	(8,602,646)
Unrealized gain (loss) on securities			(14,710)		(14,710)
Balance at end of period at Mar. 31, 2018	$ 69,428	$ 488,929,377	$ (79,143)	$ (317,217,775)	$ 171,701,887
Balances (in shares) at Mar. 31, 2018	69,427,773