Summary of Company's Warrants Outstanding (Detail)							6 Months Ended
	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Jun. 30, 2014 Minimum of Price Range [Member]	Jun. 30, 2014 Maximum of Price Range [Member]
Class of Warrant or Right [Line Items]
Warrants Outstanding, Issue Date							Jan. 30, 2009	Aug. 25, 2009
Exercise Price of Warrants Issued							6.96	10.68
Outstanding Warrants	501,494	633,740	791,508	2,628,923	3,093,676	3,127,618	65,325	436,169
Warrant Expiration Date							Jul. 30, 2014	Aug. 31, 2014