Amount of initial cost not yet recognized for nonvested award under share-based payment arrangement.

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Represents the total fair value of other than stock (or unit) option plans granted during the reporting period.

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Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

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Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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Amount of cost to be recognized for nonvested award under share-based payment arrangement. Excludes share and unit options.

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Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

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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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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Per share or unit weighted-average fair value of nonvested award under share-based payment arrangement. Excludes share and unit options.

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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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Fair value of share-based awards for which the grantee gained the right by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash.

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The estimated dividend rate (a percentage of the share price) to be paid (expected dividends) to holders of the underlying shares over the option's term.

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The estimated measure of the maximum percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period.

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The estimated measure of the minimum percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period.

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The maximum risk-free interest rate assumption that is used in valuing an option on its own shares.

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The minimum risk-free interest rate assumption that is used in valuing an option on its own shares.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Number of equity instruments other than options outstanding, including both vested and non-vested instruments.

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Number of shares authorized for issuance under share-based payment arrangement.

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Percentage of vesting of award under share-based payment arrangement.

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Expected term of award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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Stock Based Compensation (Details) - USD ($)	1 Months Ended		3 Months Ended			9 Months Ended		12 Months Ended
Stock Based Compensation (Details) - USD ($)	Aug. 31, 2020	Jun. 30, 2020	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019	Dec. 31, 2017
Restricted stock and RSU grants:
Weighted average per share value of non-vested shares (based on grant price) (in dollars per share)			$ 24.98	$ 24.98		$ 24.98	$ 24.98
Value of stock vested during the year (based on grant price)				$ 61,500		$ 3,589,000	$ 2,365,000
Weighted average per share value of shares forfeited during the year (based on grant price) (in dollars per share)				$ 24.41		$ 24.03	$ 24.41
Awards granted in 2020
Valuation assumptions
Expected life						3 years
Dividend rate						10.40%
Risk-free interest rate minimum						0.10%
Risk-free interest rate maximum						0.18%
Expected price volatility minimum						51.24%
Expected price volatility maximum						77.92%
Restricted stock and RSU grants
Total charge to operations:
Total charge to operations			$ 1,136,000	$ 942,000		$ 3,441,000	$ 2,834,000
Restricted stock
Stock Based Compensation
Vesting period						5 years
Number of shares forfeited				12,400			12,400
Number of shares vested				2,500		122,125	114,650
Summary of the activity of the incentive plans
Average per share grant price (in dollars per share)						$ 28.10	$ 25.70
Deferred compensation to be recognized over vesting period			$ 4,202,000	$ 3,856,000		$ 4,202,000	$ 3,856,000
Number of non-vested shares:
Non-vested beginning of period (in shares)			701,675	689,150		674,250	651,250	651,250
Number of shares awarded						149,550	150,050
Forfeitures (in shares)				(12,400)			(12,400)
Non-vested end of period (in shares)		701,675	701,675	674,250		701,675	674,250	674,250
Vested during year (in shares)				(2,500)		(122,125)	(114,650)
Total charge to operations:
Total charge to operations			$ 885,000	$ 717,000		$ 2,644,000	$ 2,403,000
Total compensation costs related to non-vested awards that have not yet been recognized			$ 8,698,000			$ 8,698,000
Weighted average remaining vesting period						2 years 4 months 24 days
RSUs
Stock Based Compensation
Number of shares forfeited						51,907		5,250
Number of shares vested						24,343
Summary of the activity of the incentive plans
Average per share grant price (in dollars per share)			$ 17.31	$ 28.96		$ 17.31	$ 28.96
Deferred compensation to be recognized over vesting period			$ 861,000	$ 923,000		$ 861,000	$ 923,000
Number of non-vested shares:
Non-vested beginning of period (in shares)			148,776	152,500		225,026	152,500	152,500
Number of shares awarded			75,026	77,776	76,250	75,026	77,776
Forfeitures (in shares)						(51,907)		(5,250)
Non-vested end of period (in shares)		148,776	223,802	230,276		223,802	230,276	225,026
Vested during year (in shares)						(24,343)
Total charge to operations:
Total charge to operations			$ 251,000	$ 225,000		$ 797,000	$ 431,000
Total compensation costs related to non-vested awards that have not yet been recognized			$ 1,643,000			$ 1,643,000
Weighted average remaining vesting period						1 year 9 months 18 days
RSUs \| Awards granted in 2020, 2019 and 2018
Stock Based Compensation
Number of shares forfeited						0
Number of shares vested						0
Number of non-vested shares:
Forfeitures (in shares)						0
Vested during year (in shares)						0
TSR Awards
Stock Based Compensation
Percentage of RSUs to vest upon achievement of specified criteria						50.00%
ROC Awards
Stock Based Compensation
Percentage of RSUs to vest upon achievement of specified criteria						50.00%
2019 Incentive Plan
Stock Based Compensation
Maximum number of shares authorized for issuance			750,000			750,000
Shares subject to awards outstanding			299,602			299,602
2019 Incentive Plan \| Restricted stock
Stock Based Compensation
Shares subject to awards outstanding			149,550			149,550
2019 Incentive Plan \| RSUs
Stock Based Compensation
Shares subject to awards outstanding			150,052			150,052
2016 and 2012 Incentive Plans
Number of non-vested shares:
Non-vested end of period (in shares)			625,875			625,875
2016 and 2012 Incentive Plans \| Restricted stock
Number of non-vested shares:
Non-vested end of period (in shares)			552,125			552,125
2016 and 2012 Incentive Plans \| RSUs
Stock Based Compensation
Number of shares forfeited	51,907
Number of shares vested		24,343
Number of non-vested shares:
Number of shares awarded									76,250
Forfeitures (in shares)	(51,907)
Non-vested end of period (in shares)			73,750			73,750
Vested during year (in shares)		(24,343)
Pay-for-performance program \| RSUs \| Awards granted in 2020
Stock Based Compensation
Aggregate fair value of the shares granted			$ 861,000			$ 861,000
Pay-for-performance program \| RSUs \| Awards granted in 2019
Stock Based Compensation
Aggregate fair value of the shares granted			1,014,000			1,014,000
Pay-for-performance program \| RSUs \| Awards granted in 2018
Stock Based Compensation
Aggregate fair value of the shares granted			$ 945,000			$ 945,000