Fair Value Measurements - Summary of Reconciliation of Warrant Liability Measured at Fair Value on Recurring Basis Using Significant Unobservable Inputs (Detail) - Fair Value Measurement, Recurring [Member] - Warrant Liability [Member]	12 Months Ended
	Dec. 31, 2018 USD ($)
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Beginning balance	$ 3,701,277
Change in fair value upon re-measurement	(433,392)
Reclassification to Additional Paid-in Capital due to warrant amendment	$ (3,267,885)