Summary of Information about Warrants Outstanding (Detail)	9 Months Ended
	Sep. 30, 2013
Class of Warrant or Right [Line Items]
Outstanding Warrants	959,283
Exercisable Warrants	959,283
$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	232,103
Warrant expiration date	Jul. 30, 2014
Weighted Average Remaining Contractual Life (Years)	9 months 18 days
Exercisable Warrants	232,103
$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	727,180
Warrant expiration date	Aug. 31, 2014
Weighted Average Remaining Contractual Life (Years)	10 months 24 days
Exercisable Warrants	727,180