Subsequent Event-Public Offering of Common Stock and Warrants - Additional Information (Detail) (USD $)	12 Months Ended		0 Months Ended		3 Months Ended	0 Months Ended	3 Months Ended
	Dec. 31, 2013	Sep. 23, 2013	Mar. 17, 2014 Subsequent Event [Member]	Feb. 18, 2014 Subsequent Event [Member]	Mar. 31, 2014 Subsequent Event [Member]	Feb. 18, 2014 Subsequent Event [Member] Private Placement [Member]	Mar. 31, 2014 Subsequent Event [Member] Private Placement [Member]
Subsequent Event [Line Items]
Net proceeds from issuance of common stock and warrant				$ 11,106,000
Issuance of common stock and warrant value under public offering				12,000,000
Share price of common stock and warrant issued under public offering				$ 2.05
Number of warrants issued for each unit issued under public offering				0.5
Common stock issued during period under public offering				5,853,657
Number of securities issued for warrants	2,452,431	2,452,431	989,874	2,926,829		292,682
Term of warrants	5 years			5 years
Exercise Price	2.24	2.24	2.24	2.75		2.56
Warrant exercisable period						180 days
Percentage of warrant owned				9.99%
Number of warrant exercised			989,874				2,452,431
Proceeds from warrant exercises	$ 864,000		$ 2,722,000		$ 5,500,000