Consolidated Statements of Operations (Parenthetical) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Stock-based compensation expense	$ 2,576,456	$ 1,446,549	$ 1,555,523
Research and Development Expense [Member]
Stock-based compensation expense	655,034	469,357	626,002
General and Administrative Expense [Member]
Stock-based compensation expense	$ 1,921,422	$ 977,192	$ 929,521