Securities (Schedule Of Carrying Value Of Securities Pledged As Collateral) (Details) - USD ($) $ in Thousands	Jun. 30, 2026	Sep. 30, 2025
Marketable Securities [Line Items]
AFS securities	$ 783,559	$ 867,216
Asset Pledged as Collateral [Member]
Marketable Securities [Line Items]
AFS securities	191,000	242,046
Asset Pledged as Collateral [Member] \| FRB of Kansas City borrowings [Member]
Marketable Securities [Line Items]
AFS securities	97,939	91,130
Asset Pledged as Collateral [Member] \| Public Unit Deposits [Member]
Marketable Securities [Line Items]
AFS securities	$ 93,061	$ 150,916

Amount excluding accrued interest, of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 210
-Name Accounting Standards Codification
-Section S45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477657/942-210-S45-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 210
-Name Accounting Standards Codification
-Section S50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478478/942-210-S50-1

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(6))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478546/942-210-S99-1

Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 326
-SubTopic 30
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479130/326-30-45-1

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant