Common Stock - Additional Information (Detail) - USD ($)	1 Months Ended		6 Months Ended
	May. 31, 2015	Apr. 30, 2015	Jun. 30, 2015	Jun. 30, 2014
Class of Stock [Line Items]
Proceeds from issuance of common stock and warrants		$ 25,000,000
Common stock issued in public offering		35,715,000
Exercise price of warrants		$ 0.85
Warrant expiration period		5 years
Net proceeds from issuance of common stock	$ 25,000,000		$ 24,942,963	$ 279,084
Over-Allotment-Option [Member]
Class of Stock [Line Items]
Common stock issued in public offering	2,757,250	5,357,250
Number of securities callable by warrants		4,017,938
Warrants issued for purchase of additional common shares		4,017,938
Common stock, price per share	$ 0.699	$ 0.85
Net proceeds from issuance of common stock	$ 1,800,000
Common Stock [Member]
Class of Stock [Line Items]
Number of securities callable by each warrant or right warrants		0.75