Stock Compensation Plans: Disclosure of Share-based Compensation Arrangements by Share-based Payment Award (Details) - $ / shares	6 Months Ended
Mar. 31, 2021	Mar. 31, 2020
Shares:
Options outstanding, beginning of period (shares)	395,349	378,304
Exercised (shares)	(53,564)	(36,375)
Granted (shares)	1,500	1,000
Forfeited (shares)	(4,520)	(8,650)
Options outstanding, end of period (shares)	338,765	334,279
Weighted Average Exercise Price (in dollars per share):
Options outstanding, beginning of period (dollars per share)	$ 18.45	$ 18.15
Exercised (dollars per share)	9.70	10.30
Granted (dollars per share)	19.13	26.50
Forfeited (dollars per share)	27.57	24.84
Options outstanding, end of period (dollars per share)	$ 19.71	$ 18.86

The number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan.

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Net number of share options (or share units) granted during the period.

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Number of options outstanding, including both vested and non-vested options.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
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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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Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

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Weighted average price at which option holders acquired shares when converting their stock options into shares.

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Weighted average price at which grantees could have acquired the underlying shares with respect to stock options that were terminated.

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Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options.

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Number of share options (or share units) exercised during the current period.

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