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Income Taxes - Schedule of Reconciliation between Effective Tax Rate Income from Continuing Operations and Statutory Rate (Detail) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
Income Tax Expense Benefit Continuing Operations Income Tax Reconciliation [Abstract]
Income tax expense at federal statutory rate	$ 3,878	$ 18,796	$ 8,696
(Reduction) increase in income taxes resulting from:
State taxes, net of federal tax benefit	660	1,397	792
Permanent items	63	92	71
Change in valuation allowances	(646)	531	249
US Tax Cuts and Jobs Act Impact	(22,015)
Impact of changing rates on deferred tax assets	(773)	(353)	(673)
Expired tax attributes	1,088	409	380
Other	319	2	411
(Benefit) provision for income taxes	$ (17,426)	$ 20,874	$ 9,926

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Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to increase (decrease) in the valuation allowance for deferred tax assets.

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