Stockholders' Equity - Additional Information (Detail) - USD ($)		1 Months Ended		3 Months Ended	6 Months Ended
	Jan. 24, 2016	Jan. 31, 2016	Dec. 31, 2013	Dec. 31, 2015	Dec. 31, 2015	Dec. 31, 2014
Class of Stock [Line Items]
Number of warrants					1,176,105	1,176,105
Weighted Average Exercise Price				$ 3.67	$ 3.67	$ 3.67
Outstanding warrants remaining contract life, weighted average period					10 months 24 days
Weighted-average grant date fair value, per share					$ 2.74
Options vested during the period					626,605
Unrecognized compensation expense				$ 3,000,000	$ 3,000,000
Unrecognized compensation expense weighted average period					1 year 9 months 18 days
At-the-Market Offering [Member]
Class of Stock [Line Items]
Common stock issued to investors				0	0	0
Common stock shares maximum aggregate offering price			$ 19,200,000
Common stock unsold value					$ 17,600,000
Stock issuances, sales agent commission maximum percentage			3.00%
Subsequent Event [Member]
Class of Stock [Line Items]
Common stock issued to investors		4,440,000
Common stock price per share		$ 4.00
Gross proceeds from issuance of common stock		$ 17,800,000
Estimated share issuance costs		$ 1,400,000
Number of Warrants, Expired	552,500
Exercise price of expired warrants	$ 5.00
Minimum [Member]
Class of Stock [Line Items]
Remaining contractual life of warrants					24 days
Maximum [Member]
Class of Stock [Line Items]
Remaining contractual life of warrants					1 year 7 months 6 days
2008 Incentive Plan [Member]
Class of Stock [Line Items]
Number of common stock, authorized for issuance				7,091,255	7,091,255
Shares available for grant				1,027,791	1,027,791
Options granted with annual vesting					846,000
Contractual life of option grants					10 years
2008 Incentive Plan [Member] | Employees [Member]
Class of Stock [Line Items]
Options granted with annual vesting					736,000
Ratable annual vesting period of granted options					4 years
2008 Incentive Plan [Member] | Non-executive Directors [Member]
Class of Stock [Line Items]
Options granted with annual vesting					110,000
Ratable annual vesting period of granted options					1 year