Net Loss Per Common Share - Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share (Detail) - shares	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total antidilutive securities excluded from the computation of earnings per share (in shares)	5,858,005	925,400	6,512,894	861,153
Convertible preferred stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total antidilutive securities excluded from the computation of earnings per share (in shares)	4,915,974	0	5,567,960	0
Warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total antidilutive securities excluded from the computation of earnings per share (in shares)	459,375	459,375	459,375	459,375
Options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total antidilutive securities excluded from the computation of earnings per share (in shares)	482,656	466,025	485,559	401,778