Fair Value of Financial Instruments - Schedule of Roll Forward of Warrant Liability Classified as Level 3 and Measured at Fair Value on a Recurring Basis (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2016 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Change in fair value of warrant liability	$ (910)
Fair Value, Measurements, Recurring [Member] | Basis of Fair Value Measurements, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Issuances	2,120
Change in fair value of warrant liability	(910)
Ending balance	$ 1,210