Stockholders' Equity - Additional Information (Detail) - USD ($)	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018	Apr. 12, 2018
Class of Stock [Line Items]
Common Stock, Shares, Issued	9,781,755		7,380,463
Common Stock, Value, Issued	$ 978		$ 738
Net proceeds from issuance of stock and warrants	$ 7,497	$ 0
Common stock, par value (in dollars per share)	$ 0.0001		$ 0.0001
Compensation cost not yet recognized	$ 139,588
Compensation cost not yet recognized, period for recognition	1 year 3 months 23 days
Series D Convertible Preferred Stock
Class of Stock [Line Items]
Preferred stock, shares outstanding (in shares)	11,712.23		14,052.93
Shares converted (in shares)	2,998.2
Series E Convertible Preferred Stock
Class of Stock [Line Items]
Preferred stock, shares outstanding (in shares)	0		7,000
Shares converted (in shares)	3,260.7	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 D Convertible Preferred Stock
Class of Stock [Line Items]
Convertible preferred stock, shares issued upon conversion (in shares)	(1,140,000)
Common Stock | Series E Convertible Preferred Stock
Class of Stock [Line Items]
Convertible preferred stock, shares issued upon conversion (in shares)	(1,239,810)	(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