Stockholders' Equity - Summary of Warrants Issued and Outstanding (Detail) - $ / shares	6 Months Ended
	Jun. 30, 2015	May. 28, 2014	May. 07, 2014
Class Of Warrant Or Right [Line Items]
Exercise Price		$ 4.31	$ 2.65
Shares of Common Stock	11,791,000
Exercisable Warrants [Member]
Class Of Warrant Or Right [Line Items]
Shares of Common Stock	11,791,000
Exercisable Warrants [Member] | Warrants One [Member]
Class Of Warrant Or Right [Line Items]
Date of Issuance	Apr. 18, 2014
Date of Expiration	Apr. 01, 2017
Exercise Price	$ 2.00
Shares of Common Stock	1,441,000
Exercisable Warrants [Member] | Warrant Two [Member]
Class Of Warrant Or Right [Line Items]
Date of Issuance	May 07, 2014
Date of Expiration	May 07, 2017
Exercise Price	$ 2.65
Shares of Common Stock	200,000
Exercisable Warrants [Member] | Warrants Three [Member]
Class Of Warrant Or Right [Line Items]
Date of Issuance	May 28, 2014
Date of Expiration	Oct. 31, 2016
Exercise Price	$ 4.31
Shares of Common Stock	450,000
Exercisable Warrants [Member] | Warrants Four [Member]
Class Of Warrant Or Right [Line Items]
Date of Issuance	Sep. 24, 2014
Date of Expiration	Sep. 24, 2019
Exercise Price	$ 2.50
Shares of Common Stock	9,000,000
Exercisable Warrants [Member] | Warrant Five [Member]
Class Of Warrant Or Right [Line Items]
Date of Issuance	Oct. 20, 2014
Date of Expiration	Oct. 20, 2019
Exercise Price	$ 2.50
Shares of Common Stock	700,000
Contingent Warrants [Member]
Class Of Warrant Or Right [Line Items]
Less warrants cancelled	(1,200,000)
Contingent Warrants [Member] | Warrant Six [Member]
Class Of Warrant Or Right [Line Items]
Date of Issuance	May 07, 2014
Date of Expiration	May 07, 2017
Exercise Price	$ 4.31
Shares of Common Stock	1,200,000