Stockholders' Equity - Additional Information (Detail) - USD ($)		3 Months Ended
	Jun. 15, 2017	Mar. 31, 2018	Dec. 31, 2017
Class Of Stock [Line Items]
Common stock, capital shares reserved for future issuance		16,230,462
Private Placement [Member]
Class Of Stock [Line Items]
Shares of common stock issued	1,552,795
Purchase price per share	$ 9.66
Aggregate purchase price	$ 15,000
Volume-weighted average trading price of common stock trading days	30 days
Percentage of volume-weighted average trading price of common stock	95.00%
Volume-weighted average trading price of common stock trading days ending on	Jun. 14, 2017
Series A Convertible Preferred Stock [Member]
Class Of Stock [Line Items]
Preferred Stock, shares authorized		1,000,000	1,000,000
Preferred stock dividends issued		0
Dividends in arrears		$ 11,000
Preferred Stock [Member]
Class Of Stock [Line Items]
Preferred Stock, shares authorized		50,000,000