Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Income Tax Disclosure [Abstract]
Valuation allowance against deferred tax assets	100.00%
Gross federal net operating loss carry forwards		$ 260.7
Gross federal estimated net operating loss carry forwards	$ 24.5
Gross state net operating loss carry forwards		$ 398.3
Gross state estimated net operating loss carry forwards	$ 24.2