Preferred Stock, Common Stock and Stockholders' Equity - Summary of Warrants Activity (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Warrants And Rights Note Disclosure [Abstract]
Warrants, Outstanding beginning balance	118,881
Warrants, Issued	3,227,876
Warrants, Exercised	(22,881)
Warrants, Outstanding ending balance	3,323,876	118,881
Weighted Average Exercise Price, Outstanding beginning balance	$ 16.73
Weighted Average Exercise Price, Issued	2.81
Weighted Average Exercise Price, Exercised	5.90
Weighted Average Exercise Price, Outstanding ending balance	$ 3.29	$ 16.73
Weighted Average Remaining Contractual Term (Years), Outstanding	4 years 11 months 16 days	4 years 4 months 6 days
Weighted Average Remaining Contractual Term (Years), Issued	5 years 15 days
Weighted Average Remaining Contractual Term (Years), Exercised	8 years