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Income Taxes - Additional Information (Detail) - USD ($)			9 Months Ended
	Jan. 31, 2018	Dec. 22, 2017	Sep. 30, 2018	May 31, 2017
Income Tax Disclosure [Line Items]
Tax benefit recognized			$ 0
U.S. federal corporate tax rate		35.00%	21.00%
Valuation allowance, deferred tax assets			$ 28,541,000
Income tax liability				$ 0
Internal Revenue Service (IRS) [Member]
Income Tax Disclosure [Line Items]
Open tax year	2015
New York State Department of Taxation [Member]
Income Tax Disclosure [Line Items]
Open tax year	2014 2015 2016