Equity Transactions - Additional Information (Detail) - USD ($)					3 Months Ended
	May 03, 2018	Apr. 19, 2018	Mar. 06, 2018	Mar. 05, 2018	Mar. 31, 2018
Class Of Stock [Line Items]
Cash proceeds from issuance of common stock, net of offering costs					$ 4,462,000
Preferred stock, dividend rate				10.00%
Subsequent Event [Member]
Class Of Stock [Line Items]
Preferred stock liquidation damage payments		$ 48,000
Warrants [Member]
Class Of Stock [Line Items]
Triggering event charges					$ 11,000
Private Placement [Member] | Common Stock [Member]
Class Of Stock [Line Items]
Common stock, issued and sold to investors			2,857,144
Common stock, price per share			$ 1.75
Private Placement [Member] | Common Stock [Member] | Subsequent Event [Member]
Class Of Stock [Line Items]
Common stock, issued and sold to investors	3,170,000
Common stock, price per share	$ 2.21
Offering [Member]
Class Of Stock [Line Items]
Gross proceeds before deducting placement agent fee and offering expenses			$ 5,000,000
Cash proceeds from issuance of common stock, net of offering costs			$ 4,475,000
Offering [Member] | Unterberg Koller Capital Fund L.P. [Member] | Maximum [Member]
Class Of Stock [Line Items]
Common stock exercise price			$ 2.14
Offering [Member] | Unterberg Koller Capital Fund L.P. [Member] | Minimum [Member]
Class Of Stock [Line Items]
Common stock exercise price			2.07
Offering [Member] | Common Stock [Member]
Class Of Stock [Line Items]
Common stock exercise price			2.17
Chardan Capital Markets, LLC [Member]
Class Of Stock [Line Items]
Common stock exercise price			$ 2.365
Percentage of gross proceeds of offering			8.00%
Percentage of warrants to purchase shares of common stock on number of shares sold			3.00%
Warrants term			5 years 6 months
Chardan Capital Markets, LLC [Member] | Subsequent Event [Member]
Class Of Stock [Line Items]
Percentage of gross proceeds of offering	7.00%