Summary of Significant Accounting Policies - Detail 2 (Details) - shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive common stock equivalents	11,778,846	25,215,812
Stock options, warrants and restricted stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive common stock equivalents	2,997,330	16,434,296
Series A redeemable convertible preferred stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive common stock equivalents	8,781,516	8,781,516