Income Taxes - Schedule of Reconciliation of Income Tax Provision to Statutory Federal Income Tax Rate (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Expense Benefit Continuing Operations Income Tax Reconciliation [Abstract]
Income taxes at statutory rates	$ 396,760	$ 1,272,242	$ (91,705)
State income tax, net of federal benefit	3,910	2,054	411
Permanent items	(5,060)	68,944	32,530
Meals and entertainment	74,755	54,375	40,796
Equity based compensation	(645,512)	48,385	98,637
Warrant liability		(156,498)	(34,160)
Corporate tax rate change - impact on deferred income taxes	2,768,458
Research and development credit	206,801	(141,494)	628,573
Federal NOL adjustment	(386,441)	(206,133)
Federal return to provision	53,265	11,104
Other federal credits	112,262
Other	15,695
Change in federal valuation allowance	(2,569,208)	(944,798)	(674,460)
Total tax provision	$ 25,685	$ 8,181	$ 622