Income Taxes - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Income Tax [Line Items]
Tax provision or benefit	$ 0	$ 0
Federal income tax benefit	$ 14,267	14,267
Limit of utilization of net operating losses (NOLs) and tax credits description	Under the rules, such an ownership change is generally any change in ownership of more than 50% of a company’s stock within a rolling three-year period. The rules generally operate by focusing on changes in ownership among stockholders considered by the rules as owning, directly or indirectly, 5% or more of the stock of a company and any change in ownership arising from new issuances of stock by the company.
Liabilities for unrecognized tax benefits	$ 0	$ 0
Federal [Member]
Income Tax [Line Items]
Net operating loss carryforwards	$ 94,659,000
Operating loss carryforwards expiration year	2029
Federal [Member] | Research and Development Tax Credit Carryforwards [Member]
Income Tax [Line Items]
Tax credit carryforwards	$ 5,202,362
Tax credit expiration year	2029
State and Local Jurisdiction [Member]
Income Tax [Line Items]
Net operating loss carryforwards	$ 88,945,478
Operating loss carryforwards expiration year	2030
State and Local Jurisdiction [Member] | Research and Development Tax Credit Carryforwards [Member]
Income Tax [Line Items]
Tax credit carryforwards	$ 2,841,187
Tax credit expiration year	2025