Stockholders' Equity - Schedule of Warrant Activity (Detail)	6 Months Ended
	Jun. 30, 2020 shares
Class Of Warrant Or Right [Line Items]
Beginning Balance	7,070,680
Issued	7,243,135
Exercised	(6,898,224)
Cancelled/Expired	0
Ending Balance	7,415,591
Registered Direct Warrants, Series A [Member]
Class Of Warrant Or Right [Line Items]
Beginning Balance	3,449,112
Issued	0
Exercised	(3,449,112)
Cancelled/Expired	0
Ending Balance	0
Registered Direct Warrants, Series B [Member]
Class Of Warrant Or Right [Line Items]
Beginning Balance	3,449,112
Issued	0
Exercised	(3,449,112)
Cancelled/Expired	0
Ending Balance	0
Registered Direct Warrants, Placement Agent [Member]
Class Of Warrant Or Right [Line Items]
Beginning Balance	172,456
Issued	0
Exercised	0
Cancelled/Expired	0
Ending Balance	172,456
Private Placement Warrants [Member]
Class Of Warrant Or Right [Line Items]
Beginning Balance	0
Issued	6,898,224
Exercised	0
Cancelled/Expired	0
Ending Balance	6,898,224
Private Placement Warrants, Placement Agent [Member]
Class Of Warrant Or Right [Line Items]
Beginning Balance	0
Issued	344,911
Exercised	0
Cancelled/Expired	0
Ending Balance	344,911