Income Taxes - Principal Reasons for Differences from Federal Statutory Rate (Detail)	12 Months Ended
Sep. 30, 2016	Sep. 30, 2015
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Federal tax at statutory rate	35.00%	35.00%
True-up of prior year's tax provision	(1.80%)	(2.10%)
State tax at statutory rate	2.60%	3.90%
Permanent and other differences	0.30%	0.20%
Uncertain tax position allowance	0.20%	2.40%
Effective Tax Rate	36.30%	39.40%

Effective income tax rate reconciliation permanent and other differences.

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

+ References

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-Publisher FASB
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Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

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Percentage 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 changes in the valuation allowance for deferred tax assets.

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Percentage 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 revisions of previously reported income tax expense.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Percentage 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 applicable to state and local income tax expense (benefit), net of federal tax expense (benefit).

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