Subsequent Events - Additional Information (Detail) - USD ($)			3 Months Ended
	May 03, 2018	Mar. 06, 2018	Mar. 31, 2018	Dec. 31, 2017
Subsequent Event [Line Items]
Common stock, par value			$ 0.001	$ 0.001
Cash proceeds from issuance of common stock, net of offering costs			$ 4,462,000
Chardan Capital Markets, LLC [Member]
Subsequent Event [Line Items]
Common stock exercise price		$ 2.365
Percentage of gross proceeds of offering		8.00%
Common Stock [Member] | Private Placement [Member]
Subsequent Event [Line Items]
Common stock, issued and sold to investors		2,857,144
Common stock, price per share		$ 1.75
Subsequent Event [Member]
Subsequent Event [Line Items]
Resale registration statement declared description	The Company will use its reasonable best efforts to cause the Resale Registration Statement to be declared effective by the SEC within 30 days after the filing thereof (60 days in the event the registration statement is reviewed by the SEC).
Subsequent Event [Member] | Private Placement [Member]
Subsequent Event [Line Items]
Common stock, par value	$ 0.001
Subsequent Event [Member] | May 2018 Offering [Member]
Subsequent Event [Line Items]
Gross proceeds before deducting placement agent fee and offering expenses	$ 7,000,000
Cash proceeds from issuance of common stock, net of offering costs	$ 6,300,000
Subsequent Event [Member] | May 2018 Offering [Member] | Roth Capital Partners L L C
Subsequent Event [Line Items]
Percentage of gross proceeds of offering	2.00%
Subsequent Event [Member] | Chardan Capital Markets, LLC [Member]
Subsequent Event [Line Items]
Percentage of gross proceeds of offering	7.00%
Subsequent Event [Member] | Common Stock [Member] | Private Placement [Member]
Subsequent Event [Line Items]
Common stock, issued and sold to investors	3,170,000
Common stock, price per share	$ 2.21
Subsequent Event [Member] | Common Stock [Member] | May 2018 Offering [Member]
Subsequent Event [Line Items]
Common stock exercise price	$ 2.11