Summary of Outstanding Warrants Issued (Detail) - $ / shares	3 Months Ended
	Mar. 31, 2015	Aug. 14, 2013	Nov. 30, 2010
Class Of Warrant Or Right [Line Items]
Number of Shares Issuable Upon Exercise	741,047
Weighted Average Exercise Price		$ 10.00	$ 26.50
Consultant Warrant
Class Of Warrant Or Right [Line Items]
Number of Shares Issuable Upon Exercise	85,000
Weighted Average Exercise Price	$ 10.70
Issue Date	Aug. 13, 2014
Expiration Date	Aug. 13, 2019
Opus Warrant
Class Of Warrant Or Right [Line Items]
Number of Shares Issuable Upon Exercise	100,000
Weighted Average Exercise Price	$ 9.90
Issue Date	Mar. 31, 2014
Expiration Date	Mar. 31, 2019
2013 Private Placement Warrants
Class Of Warrant Or Right [Line Items]
Number of Shares Issuable Upon Exercise	186,878
Weighted Average Exercise Price	$ 10.00
Issue Date	Aug. 14, 2013
Expiration Date	Aug. 14, 2017
2010 Private Placement Warrants
Class Of Warrant Or Right [Line Items]
Number of Shares Issuable Upon Exercise	369,169
Weighted Average Exercise Price	$ 26.50
Issue Date	Nov. 14, 2010
Expiration Date	Nov. 14, 2015