Warrants - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended		12 Months Ended
	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2009
Class of Warrant or Right [Line Items]
Warrants to purchase an aggregate of shares of common stock				8,206,520
Warrant term				5 years
Warrants expiration date		2014-12
Change in fair value of warrants	$ 5,600		$ 5,682
Warrants exercised			43,300
Conversion of Warrants to Common Stock			21,977
J. P. Morgan Securities LLC
Class of Warrant or Right [Line Items]
Warrants issued				464,520