Equity Transactions - Additional Information (Detail) $ / shares in Units, $ in Thousands			6 Months Ended
	May 17, 2017 USD ($)	May 16, 2017 Investor $ / shares shares	Jun. 30, 2017 USD ($) $ / shares
Class Of Stock [Line Items]
Warrants term			5 years
Warrants exercisable beginning date			Nov. 18, 2017
Gross proceeds before deducting transaction fees and other expenses	$ 2,300
Offering cost related to the transaction	200
Transaction fees	100
Legal and other expenses	100
Cash received from stock offering, net of expenses	$ 2,100		$ 2,056
Registered Direct Offering [Member]
Class Of Stock [Line Items]
Common stock, issued and sold to investors | shares		2,077,000
Common stock, price per share | $ / shares		$ 1.05
Private Placement [Member]
Class Of Stock [Line Items]
Common stock, issued and sold to investors | shares		85,000
Common stock, price per share | $ / shares		$ 1.10
Number of accredited investors | Investor		4
Sutter [Member]
Class Of Stock [Line Items]
Percentage of warrants to purchase shares of common stock on number of shares sold			5.00%
Common stock exercise price | $ / shares			$ 1.21
Chardan [Member]
Class Of Stock [Line Items]
Percentage of warrants to purchase shares of common stock on number of shares sold			5.00%
Common stock exercise price | $ / shares			$ 1.155