Investment Securities: Other than Temporary Impairment, Credit Losses Recognized in Earnings (Details) - USD ($) $ in Thousands	12 Months Ended
Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2022
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Balance, beginning of year	$ 816	$ 836	$ 853
Net realized gain (losses) previously recorded as credit losses	(2)	(11)	1
Recovery of prior credit loss	(11)	(9)	(18)
Balance, end of year	$ 803	$ 816	$ 836

Other Than Temporary Impairment, Credit Losses Recognized In Earnings, Net Realized Gain (Loss)

No definition available.

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- Definition

Amount of accumulated credit loss recognized in earnings for debt security held for which portion of other-than-temporary impairment (OTTI) was recognized in other comprehensive income (OCI).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 8B
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481800/320-10-50-8B

Reference 2: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 8B
-Subparagraph (g)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481800/320-10-50-8B

+ Details

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- Definition

Amount of decrease in accumulated credit loss recognized in earnings for other-than-temporary impairment (OTTI) of debt security held from increase in cash flow expected to be collected and recognized over remaining life of security.

+ References

+ Details

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Data Type:	xbrli:monetaryItemType
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- Definition

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

+ References

No definition available.

+ Details

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