Warrants - Summary of Warrant Activity (Detail)	6 Months Ended
	Jun. 30, 2020 shares
Equity [Abstract]
Warrants outstanding, December 31, 2019	10,384,706
Warrants issued due to anti-dilution features triggered from Registered Direct Offering	1,358
Exercises	(8,235,779)
Warrants outstanding, June 30, 2020	2,150,285