Stockholders' Equity - Additional Information (Detail) - USD ($)	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Apr. 12, 2018	Dec. 31, 2017
Class of Stock [Line Items]
Common Stock, Shares, Issued	7,365,038			2,706,066
Common Stock, Value, Issued	$ 737			$ 271
Net proceeds from issuance of stock and warrants	$ 9,254	$ 9,569,800
Common stock, par value (in dollars per share)	$ 0.0001			$ 0.0001
Compensation cost not yet recognized	$ 263,734
Compensation cost not yet recognized, period for recognition	2 years 23 days
Series D Convertible Preferred Stock
Class of Stock [Line Items]
Preferred stock, shares outstanding (in shares)	14,052.93			14,052.93
Series E Convertible Preferred Stock
Class of Stock [Line Items]
Preferred stock, shares outstanding (in shares)	3,260.7			7,000
Shares converted (in shares)	3,739.3
Series F Convertible Preferred Stock
Class of Stock [Line Items]
Preferred stock, shares outstanding (in shares)	0			7,927.05
Shares converted (in shares)	(7,927.05)
Common Stock | Series E Convertible Preferred Stock
Class of Stock [Line Items]
Convertible preferred stock, shares issued upon conversion (in shares)	(1,421,787)
Common Stock | Series F Convertible Preferred Stock
Class of Stock [Line Items]
Convertible preferred stock, shares issued upon conversion (in shares)	(3,014,087)
Management Incentive [Member]
Class of Stock [Line Items]
Common Stock, Shares, Issued	214,791
Common Stock, Value, Issued	$ 294,264
Stock Price (in dollars per share)			$ 1.37