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Allowance for Credit Losses - Allowance for Credit Losses and Balance of Loans Receivable (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2021
Financing Receivable, Allowance for Credit Losses [Line Items]
Total allowance for credit losses	$ 44,939	$ 48,734	$ 47,058	$ 58,165
Loans individually analyzed	39,900
Total	5,748,750	5,850,476
Unaccreted yield adjustments	(15,963)	(21,055)
Total loans receivable, net of yield adjustments	5,732,787	5,829,421
Commercial business \| Multi-family mortgage
Financing Receivable, Allowance for Credit Losses [Line Items]
Total allowance for credit losses	24,125	26,362
Total	2,645,851	2,761,775
Commercial business \| Nonresidential mortgage
Financing Receivable, Allowance for Credit Losses [Line Items]
Total allowance for credit losses	6,125	8,953
Total	948,075	968,574
Commercial business \| Commercial business
Financing Receivable, Allowance for Credit Losses [Line Items]
Total allowance for credit losses	1,573	1,440
Total	142,747	146,861
Commercial business \| Construction
Financing Receivable, Allowance for Credit Losses [Line Items]
Total allowance for credit losses	1,230	1,336
Total	209,237	226,609
One- to four-family residential mortgage
Financing Receivable, Allowance for Credit Losses [Line Items]
Total allowance for credit losses	11,461	10,237	7,540	9,747
Total	1,756,051	1,700,559
Consumer loans:
Financing Receivable, Allowance for Credit Losses [Line Items]
Total	46,789	46,098
Consumer loans: \| Home equity loans
Financing Receivable, Allowance for Credit Losses [Line Items]
Total allowance for credit losses	349	338	245	433
Total	44,104	43,549
Consumer loans: \| Other consumer
Financing Receivable, Allowance for Credit Losses [Line Items]
Total allowance for credit losses	76	68	$ 84	$ 36
Total	2,685	2,549
Receivables Acquired with Deteriorated Credit Quality
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually analyzed	9	3
Loans collectively evaluated	132	211
Loans individually analyzed	1,584	928
Loans collectively evaluated	14,105	17,967
Receivables Acquired with Deteriorated Credit Quality \| Commercial business \| Multi-family mortgage
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually analyzed	0	0
Loans collectively evaluated	0	0
Loans individually analyzed	0	0
Loans collectively evaluated	0	0
Receivables Acquired with Deteriorated Credit Quality \| Commercial business \| Nonresidential mortgage
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually analyzed	0	0
Loans collectively evaluated	31	70
Loans individually analyzed	284	333
Loans collectively evaluated	2,145	3,562
Receivables Acquired with Deteriorated Credit Quality \| Commercial business \| Commercial business
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually analyzed	0	0
Loans collectively evaluated	6	9
Loans individually analyzed	0	0
Loans collectively evaluated	2,794	4,237
Receivables Acquired with Deteriorated Credit Quality \| Commercial business \| Construction
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually analyzed	0	0
Loans collectively evaluated	0	0
Loans individually analyzed	0	0
Loans collectively evaluated	5,735	5,735
Receivables Acquired with Deteriorated Credit Quality \| One- to four-family residential mortgage
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually analyzed	9	3
Loans collectively evaluated	95	132
Loans individually analyzed	1,276	570
Loans collectively evaluated	3,431	4,433
Receivables Acquired with Deteriorated Credit Quality \| Consumer loans: \| Home equity loans
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually analyzed	0	0
Loans collectively evaluated	0	0
Loans individually analyzed	24	25
Loans collectively evaluated	0	0
Receivables Acquired with Deteriorated Credit Quality \| Consumer loans: \| Other consumer
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually analyzed	0	0
Loans collectively evaluated	0	0
Loans individually analyzed	0	0
Loans collectively evaluated	0	0
Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually analyzed	853	3,417
Loans collectively evaluated	43,945	45,103
Loans individually analyzed	38,293	41,699
Loans collectively evaluated	5,694,768	5,789,882
Financial Asset, Other than Financial Asset Acquired with Credit Deterioration \| Commercial business \| Multi-family mortgage
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually analyzed	0	326
Loans collectively evaluated	24,125	26,036
Loans individually analyzed	22,591	19,114
Loans collectively evaluated	2,623,260	2,742,661
Financial Asset, Other than Financial Asset Acquired with Credit Deterioration \| Commercial business \| Nonresidential mortgage
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually analyzed	517	3,001
Loans collectively evaluated	5,577	5,882
Loans individually analyzed	9,539	16,207
Loans collectively evaluated	936,107	948,472
Financial Asset, Other than Financial Asset Acquired with Credit Deterioration \| Commercial business \| Commercial business
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually analyzed	228	20
Loans collectively evaluated	1,339	1,411
Loans individually analyzed	714	252
Loans collectively evaluated	139,239	142,372
Financial Asset, Other than Financial Asset Acquired with Credit Deterioration \| Commercial business \| Construction
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually analyzed	0	0
Loans collectively evaluated	1,230	1,336
Loans individually analyzed	0	0
Loans collectively evaluated	203,502	220,874
Financial Asset, Other than Financial Asset Acquired with Credit Deterioration \| One- to four-family residential mortgage
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually analyzed	108	70
Loans collectively evaluated	11,249	10,032
Loans individually analyzed	5,429	6,101
Loans collectively evaluated	1,745,915	1,689,455
Financial Asset, Other than Financial Asset Acquired with Credit Deterioration \| Consumer loans: \| Home equity loans
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually analyzed	0	0
Loans collectively evaluated	349	338
Loans individually analyzed	20	25
Loans collectively evaluated	44,060	43,499
Financial Asset, Other than Financial Asset Acquired with Credit Deterioration \| Consumer loans: \| Other consumer
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans individually analyzed	0	0
Loans collectively evaluated	76	68
Loans individually analyzed	0	0
Loans collectively evaluated	$ 2,685	$ 2,549