Stockholders' Equity - Summary of Warrants Issued and Outstanding (Detail) - $ / shares	9 Months Ended
	Sep. 30, 2016	Mar. 30, 2016
Class Of Warrant Or Right [Line Items]
Exercise Price		$ 3.88
Shares of Common Stock	1,994,941
Exercisable Warrants [Member]
Class Of Warrant Or Right [Line Items]
Shares of Common Stock	1,994,941
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	$ 16.00
Shares of Common Stock	180,126
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	$ 21.20
Shares of Common Stock	25,000
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	$ 34.48
Shares of Common Stock	56,250
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	$ 20.00
Shares of Common Stock	1,125,005
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	$ 20.00
Shares of Common Stock	87,500
Exercisable Warrants [Member] | Warrant Six [Member]
Class Of Warrant Or Right [Line Items]
Date of Issuance	Mar. 30, 2016
Date of Expiration	Mar. 30, 2021
Exercise Price	$ 3.88
Shares of Common Stock	521,060