Stock Based Incentive Compensation - Summary data of nonvested stock award activity (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
Nonvested Shares
Nonvested shares outstanding, number of nonvested shares	154,352	179,821
Granted, number of nonvested shares	108,000	72,000
Vested, number of nonvested shares	(68,867)	(80,969)
Forfeited, number of nonvested shares	(2,750)	(16,500)
Nonvested shares outstanding, number of nonvested shares	190,735	154,352	179,821
Vested	400,700
Vested and expected to vest	591,435
Weighted Average Grant-Date Fair Value
Nonvested shares outstanding, weighted average grant date fair value (in Dollars per share)	$ 10.34	$ 8.64
Granted, weighted average grant date fair value (in Dollars per share)	9.98	11.83
Forfeited, weighted average grant date fair value (in Dollars per share)	8.91	8.90
Vested, weighted average grant date fair value (in Dollars per share)	10.39	8.18
Nonvested shares outstanding, weighted average grant date fair value (in Dollars per share)	10.12	$ 10.34	$ 8.64
Vested (in Dollars per share)	7.17
Vested and expected to vest (in Dollars per share)	$ 8.12
Nonvested shares outstanding, weighted average remaining contractual term	2 years 2 months 16 days	2 years 1 month 10 days	2 years 2 months 23 days
Vested - Weighted Average Remaining Contractual Term	2 months 12 days
Vested and expected to vest - Weighted Average Remaining Contractual Term	10 months 6 days
Nonvested shares outstanding, aggregate intrinsic value (in Dollars)	$ 2,560	$ 2,025	$ 1,987
Vested - Intrinsic Value (in Dollars)	5,377
Vested and expected to vest - Intrinsic Value (in Dollars)	7,937
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized (in Dollars)	$ 1,400
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized, Period for Recognition	2 years 6 months
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested in Period, Fair Value (in Dollars)	$ 716	$ 662

Intrinsic value of nonvested share awards outstanding that have subsequently become vested

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Intrinsic value of nonvested share awards outstanding that have subsequently become vested or are expected be become vested

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Number of nonvested share awards outstanding that have subsequently become vested or are expected be become vested

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Weighted Average Remaining Contractual Term of nonvested share awards outstanding that have subsequently become vested or are expected be become vested

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Vested and expected to vest shares, weighted average grant date fair value

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Number of nonvested share awards that have subsequently vested

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Grant date fair value per share of nonvested share awards that have subsequently vested

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Vested, weighted average remaining contractual term

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Unrecognized cost of unvested share-based compensation awards.

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Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period.

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Weighted average fair value as of the grant date of equity-based award plans other than stock (unit) option plans that were not exercised or put into effect as a result of the occurrence of a terminating event.

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The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

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The weighted average fair value of nonvested awards on equity-based plans excluding option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, revenue or profit achievement stock award plan) for which the employer is contingently obligated to issue equity instruments or transfer assets to an employee who has not yet satisfied service or performance criteria necessary to gain title to proceeds from the sale of the award or underlying shares or units.

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Weighted average remaining contractual term for equity-based awards excluding options, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period.

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The weighted average fair value as of grant date pertaining to an equity-based award plan other than a stock (or unit) option plan for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement.

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Intrinsic value of equity-based compensation awards not vested. Excludes stock and unit options.

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Fair value of options vested. Excludes equity instruments other than options, for example, but not limited to, share units, stock appreciation rights, restricted stock.

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