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Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Amount excluding accrued interest, of allowance for credit loss on financing receivable. Excludes net investment in lease.

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Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 326
-SubTopic 20
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Amortized cost excluding accrued interest, before allowance for credit loss, fee, and loan in process, of financing receivable. Excludes net investment in lease.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 210
-Name Accounting Standards Codification
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-Paragraph 1
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Amount of unamortized loan commitment, origination, and other costs (fees) on financing receivable recognized as adjustment to yield. Excludes financing receivable covered under loss sharing agreement.

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Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 310
-SubTopic 20
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-Section 45
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Amount of unamortized purchase premium (discount) on financing receivable. Excludes financing receivable covered under loss sharing agreement.

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Loans Receivable And Allowance For Credit Losses (Summary Of Loans Receivable) (Details) - USD ($) $ in Thousands	Mar. 31, 2025	Dec. 31, 2024	Sep. 30, 2024	Mar. 31, 2024	Dec. 31, 2023	Sep. 30, 2023
Loans Receivable [Line Items]
Loans receivable, gross	$ 7,894,620		$ 7,923,251
ACL	23,970	$ 24,997	23,035	$ 24,634	$ 24,178	$ 23,759
Deferred loan fees/discounts	30,276		30,336
Premiums/deferred costs	(35,531)		(37,458)
Loans receivable, net	7,875,905		7,907,338
One- to Four-Family Segment [Member]
Loans Receivable [Line Items]
Loans receivable, gross	6,117,810		6,304,670
ACL	3,562	3,757	3,673	5,060	5,248	5,328
One- to Four-Family Segment [Member] \| Originated [Member]
Loans Receivable [Line Items]
Loans receivable, gross	3,863,882		3,941,952
ACL	1,995	2,043	1,666	2,072	2,094	2,149
One- to Four-Family Segment [Member] \| Correspondent Purchased [Member]
Loans Receivable [Line Items]
Loans receivable, gross	2,117,232		2,212,587
ACL	1,446	1,583	1,861	2,793	2,948	2,972
One- to Four-Family Segment [Member] \| Bulk Purchased [Member]
Loans Receivable [Line Items]
Loans receivable, gross	119,914		127,161
ACL	121	131	146	195	206	207
One- to Four-Family Segment [Member] \| Construction [Member]
Loans Receivable [Line Items]
Loans receivable, gross	16,782		22,970
Commercial Segment [Member]
Loans Receivable [Line Items]
Loans receivable, gross	1,668,327		1,508,978
ACL	20,176	20,999	19,154	19,330	18,678	18,180
Commercial Segment [Member] \| Construction [Member]
Loans Receivable [Line Items]
Loans receivable, gross	191,904		187,676
Commercial Segment [Member] \| Commercial Real Estate [Member]
Loans Receivable [Line Items]
Loans receivable, gross	1,340,539		1,191,624
Commercial Segment [Member] \| Commercial and Industrial [Member]
Loans Receivable [Line Items]
Loans receivable, gross	135,884		129,678
Consumer Segment [Member]
Loans Receivable [Line Items]
Loans receivable, gross	108,483		109,603
ACL	232	$ 241	208	$ 244	$ 252	$ 251
Consumer Segment [Member] \| Home Equity [Member]
Loans Receivable [Line Items]
Loans receivable, gross	99,049		99,988
Consumer Segment [Member] \| Other [Member]
Loans Receivable [Line Items]
Loans receivable, gross	$ 9,434		$ 9,615