Description of Business and Basis of Presentation - Additional Information (Detail) - USD ($)	12 Months Ended		24 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2019
Organization And Basis Of Presentation [Line Items]
Substantial Doubt about Going Concern, within One Year [true false]	true
Proceeds from Issuance or Sale of Equity	$ 4,166,868	$ 15,106
Accumulated deficit	196,881,800	194,789,605	$ 194,789,605
Cash and cash equivalents	5,226,213	$ 3,126,206	3,126,206
Attainment Of Development Milestone [Member]
Organization And Basis Of Presentation [Line Items]
Proceeds from Collaborators			$ 20,500,000
Attainment of Commercialization Milestone [Member]
Organization And Basis Of Presentation [Line Items]
Potential Proceeds From Collaborators	$ 4,500,000