Summary of Information about Warrants Outstanding (Detail)	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Class of Warrant or Right [Line Items]
Outstanding Warrants	791,508	3,127,618	4,867,477	4,944,241
$6.96
Class of Warrant or Right [Line Items]
Warrants Outstanding, Issue Date	Jan. 30, 2009
Exercise Price of warrants issued	6.96
Outstanding Warrants	133,637
Warrant expiration date	Jul. 30, 2014
$10.68
Class of Warrant or Right [Line Items]
Warrants Outstanding, Issue Date	Aug. 25, 2009
Exercise Price of warrants issued	10.68
Outstanding Warrants	657,871
Warrant expiration date	Aug. 31, 2014