Statements of Convertible Preferred Stock and Changes in Stockholders' Equity (Deficit) - USD ($)	Common Stock [Member]	Additional Paid-in Capital [Member]	Deficit Accumulated [Member]	Deficit Accumulated [Member] Convertible Preferred Stock - Series C [Member]	Deficit Accumulated [Member] Convertible Preferred Stock - Series C-1 [Member]	Deficit Accumulated [Member] Convertible Preferred Stock - Series C-2 [Member]	Total	Convertible Preferred Stock [Member]	Convertible Preferred Stock - Series C [Member]	Convertible Preferred Stock - Series C-1 [Member]	Convertible Preferred Stock - Series C-2 [Member]
Balance at Dec. 31, 2013								$ 20,680,692
Balance (in shares) at Dec. 31, 2013								8,336,865
Increase (Decrease) in Convertible Preferred Stock [Roll Forward]
Issuance of Preferred Stock, net of issuance costs										$ 14,527,016
Issuance of Preferred Stock, net of issuance costs (in shares)										3,558,890
Dividend Preferred Stock									$ 1,446,773	$ 133,928
Balance at Dec. 31, 2014								$ 36,788,409
Balance (in shares) at Dec. 31, 2014								11,895,755
Balance at Dec. 31, 2013	$ 770	$ 686,414	$ (16,036,829)				$ (15,349,645)
Balance (in shares) at Dec. 31, 2013	1,688,475
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock based compensation expense	$ 0	1,297,985	0				1,297,985
Dividend, Preferred Stock				$ (1,446,773)	$ (133,928)				(1,446,773)	(133,928)
Net loss	0	0	(12,201,386)				(12,201,386)
Balance at Dec. 31, 2014	$ 770	1,984,399	(29,818,916)				(27,833,747)
Balance (in shares) at Dec. 31, 2014	1,688,475
Increase (Decrease) in Convertible Preferred Stock [Roll Forward]
Issuance of Preferred Stock, net of issuance costs											$ 52,217,328
Issuance of Preferred Stock, net of issuance costs (in shares)											12,043,006
Other								$ 2,130
Dividend Preferred Stock									1,101,926	1,008,346	$ 2,246,136
Conversion of Preferred Stock to Common Stock upon initial public offering								$ (93,364,275)
Conversion of Preferred Stock to Common Stock upon initial public offering (in shares)								(23,938,761)
Balance at Dec. 31, 2015								$ 0
Balance (in shares) at Dec. 31, 2015								0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock based compensation expense	$ 0	2,899,304	0				2,899,304
Dividend, Preferred Stock				$ (1,101,926)	$ (1,008,346)	$ (2,246,136)			$ (1,101,926)	$ (1,008,346)	$ (2,246,136)
Conversion of Preferred Stock to Common Stock upon initial public offering	$ 6,127	93,358,148	0				93,364,275
Conversion of Preferred Stock to Common Stock upon initial public offering (in shares)	18,566,856
Initial public offering of common stock, net of issuance costs	$ 2,776	82,752,836	0				82,755,612
Initial public offering of common stock, net of issuance costs (in shares)	8,412,423
Conversion of Preferred Stock Warrant to Common Stock Warrant	$ 0	3,726,043	0				3,726,043
Issuance of common stock from exercise of stock options	$ 1	1,093	0				1,094
Issuance of common stock from exercise of stock options (in shares)	4,753
Issuance of common stock from exercise of warrants	$ 46	(46)	0				0
Issuance of common stock from exercise of warrants (in shares)	138,338
Net loss	$ 0	0	(28,078,646)				(28,078,646)
Balance at Dec. 31, 2015	$ 9,720	184,721,777	(62,253,970)				122,477,527
Balance (in shares) at Dec. 31, 2015	28,810,845
Balance at Dec. 31, 2016								$ 0
Balance (in shares) at Dec. 31, 2016								0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock based compensation expense	$ 0	5,305,070	0				5,305,070
Issuance of common stock from exercise of stock options	$ 21	293,967	0				293,988
Issuance of common stock from exercise of stock options (in shares)	63,639
Issuance of common stock from exercise of warrants	$ 15	20,955	0				$ 20,970
Issuance of common stock from exercise of warrants (in shares)	44,032						44,032
Net loss	$ 0	0	(38,820,998)				$ (38,820,998)
Balance at Dec. 31, 2016	$ 9,756	$ 190,341,769	$ (101,074,968)				$ 89,276,557
Balance (in shares) at Dec. 31, 2016	28,918,516