Stockholders' Equity - Schedule of Share-Based Compensation Shares Authorized under Warrants by Exercise Price Range (Detail)	Dec. 31, 2013
Class of Warrant or Right [Line Items]
Number of Warrants	10,534,245
Expiration Date One [Member]
Class of Warrant or Right [Line Items]
Expiration Date	Mar. 02, 2015
Class of Warrant or Right, Exercise Price of Warrants or Rights (in Dollars per Share)	1.60
Number of Warrants	935,385
Expiration Date Two [Member]
Class of Warrant or Right [Line Items]
Expiration Date	Jun. 17, 2015
Class of Warrant or Right, Exercise Price of Warrants or Rights (in Dollars per Share)	5.00
Number of Warrants	176,175
Expiration Date Three [Member]
Class of Warrant or Right [Line Items]
Expiration Date	Feb. 12, 2016
Class of Warrant or Right, Exercise Price of Warrants or Rights (in Dollars per Share)	1.60
Number of Warrants	929,826
Expiration Date Four [Member]
Class of Warrant or Right [Line Items]
Expiration Date	Mar. 19, 2016
Class of Warrant or Right, Exercise Price of Warrants or Rights (in Dollars per Share)	1.60
Number of Warrants	1,921,795
Expiration Date Five [Member]
Class of Warrant or Right [Line Items]
Expiration Date	Mar. 26, 2016
Class of Warrant or Right, Exercise Price of Warrants or Rights (in Dollars per Share)	1.60
Number of Warrants	634,189
Expiration Date Six [Member]
Class of Warrant or Right [Line Items]
Expiration Date	Jun. 22, 2016
Class of Warrant or Right, Exercise Price of Warrants or Rights (in Dollars per Share)	5.00
Number of Warrants	1,468,125
Expiration Date Seven [Member]
Class of Warrant or Right [Line Items]
Expiration Date	Oct. 24, 2017
Class of Warrant or Right, Exercise Price of Warrants or Rights (in Dollars per Share)	3.00
Number of Warrants	4,312,500
Expiration Date Eight [Member]
Class of Warrant or Right [Line Items]
Expiration Date	Sep. 30, 2018
Class of Warrant or Right, Exercise Price of Warrants or Rights (in Dollars per Share)	1.60
Number of Warrants	156,250