Consolidated Statements of Changes in Stockholders' Equity (Deficit) - USD ($)	Total	ATM Offering	2018 Underwritten Public Offering	Underwritten Public and Private Offerings	Common Stock	Common Stock ATM Offering	Common Stock 2018 Underwritten Public Offering	Common Stock Underwritten Public and Private Offerings	Additional Paid-In Capital	Additional Paid-In Capital ATM Offering	Additional Paid-In Capital 2018 Underwritten Public Offering	Additional Paid-In Capital Underwritten Public and Private Offerings	Accumulated Other Comprehensive Loss	Accumulated Deficit
Balance at Dec. 31, 2017	$ (3,059,537)				$ 13,929				$ 131,492,595					$ (134,566,061)
Balance, shares at Dec. 31, 2017					13,929,763
Exercise of stock options	316,767				$ 145				316,622
Exercise of stock options, shares					144,645
Stock-based compensation expense	1,887,764								1,887,764
Release of restricted stock awards	291				$ 291
Release of restricted stock awards, shares					291,010
Net share settlement of restricted stock award	(150,748)				$ (39)				(150,709)
Net share settlement of restricted stock award, shares					(38,582)
Stock issued under stock purchase plans	$ 199,874				$ 82				199,792
Stock issued under stock purchase plans, shares	2,304				82,261
Issuance of common stock		$ 556,706	$ 37,724,316			$ 262	$ 13,915			$ 556,444	$ 37,710,401
Issuance of common stock, shares						261,352	13,915,000
Issuance of common stock warrants in connection with MidCap Term Loan	$ 74,000								74,000
Net loss	(16,453,918)													(16,453,918)
Unrealized gain (loss) on short-term investments	(2,308)												$ (2,308)
Foreign currency translation adjustment	(1,145)												(1,145)
Balance at Dec. 31, 2018	21,092,062				$ 28,585				172,086,909				(3,453)	(151,019,979)
Balance, shares at Dec. 31, 2018					28,585,449
Exercise of stock options	120,954				$ 54				120,900
Exercise of stock options, shares					54,256
Stock-based compensation expense	1,156,486								1,156,486
Release of restricted stock awards	81				$ 81
Release of restricted stock awards, shares					81,462
Net share settlement of restricted stock award	(30,904)				$ (17)				(30,887)
Net share settlement of restricted stock award, shares					(16,927)
Stock issued under stock purchase plans	$ 171,190				$ 88				171,102
Stock issued under stock purchase plans, shares	7,500				87,456
Issuance of common stock				$ 20,758,940				$ 29,299				$ 20,729,641
Issuance of common stock, shares								29,298,537
Net loss	$ (19,297,664)													(19,297,664)
Unrealized gain (loss) on short-term investments	2,299												2,299
Foreign currency translation adjustment	(3,810)												(3,810)
Balance at Dec. 31, 2019	$ 23,969,634				$ 58,090				$ 194,234,151				$ (4,964)	$ (170,317,643)
Balance, shares at Dec. 31, 2019					58,090,233