Allowance for Credit Losses - Changes in the Allowance for Credit Losses (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2022	Dec. 31, 2021
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 47,613	$ 51,785	$ 47,058	$ 58,165
Charge-offs	(415)	(1,299)	(543)	(2,378)
Recoveries	8	150	21	249
Provision for (reversal of) credit losses	1,671	(2,420)	2,341	(7,820)
Ending balance	48,877	48,216	48,877	48,216
Commercial Loan \| Multi-family mortgage
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	26,246	24,982	25,321	28,450
Charge-offs	(395)	0	(395)	(104)
Recoveries	0	0	0	0
Provision for (reversal of) credit losses	1,647	813	2,572	(2,551)
Ending balance	27,498	25,795	27,498	25,795
Commercial Loan \| Nonresidential mortgage
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	9,152	13,845	10,590	16,243
Charge-offs	(5)	(1,284)	(15)	(2,097)
Recoveries	0	0	0	0
Provision for (reversal of) credit losses	(554)	(2,483)	(1,982)	(4,068)
Ending balance	8,593	10,078	8,593	10,078
Commercial Loan \| Commercial business
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	1,972	1,994	1,792	2,086
Charge-offs	(15)	(15)	(133)	(175)
Recoveries	5	4	17	101
Provision for (reversal of) credit losses	(143)	(80)	143	(109)
Ending balance	1,819	1,903	1,819	1,903
Commercial Loan \| Construction
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	1,120	1,430	1,486	1,170
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Provision for (reversal of) credit losses	81	11	(285)	271
Ending balance	1,201	1,441	1,201	1,441
One-to Four-Family Residential Mortgage
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	8,801	9,129	7,540	9,747
Charge-offs	0	0	0	0
Recoveries	0	145	0	147
Provision for (reversal of) credit losses	554	(673)	1,815	(1,293)
Ending balance	9,355	8,601	9,355	8,601
Consumer Loans \| Home equity loans
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	244	318	245	433
Charge-offs	0	0	0	0
Recoveries	0	1	0	1
Provision for (reversal of) credit losses	95	(11)	94	(126)
Ending balance	339	308	339	308
Consumer Loans \| Other consumer
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	78	87	84	36
Charge-offs	0	0	0	(2)
Recoveries	3	0	4	0
Provision for (reversal of) credit losses	(9)	3	(16)	56
Ending balance	$ 72	$ 90	$ 72	$ 90

Amount excluding accrued interest, of allowance for credit loss on financing receivable.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=124255206&loc=SL82895884-210446

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Amount of increase in allowance for credit loss on financing receivable from recovery.

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Amount of writeoff of financing receivable, charged against allowance for credit loss.

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Amount of credit loss expense (reversal of expense) for financing receivable.

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