ALLOWANCE FOR CREDIT LOSSES - Changes in the Allowance for Credit Losses (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Mar. 31, 2023	Mar. 31, 2022
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 48,877	$ 48,216	$ 47,058	$ 58,165
Charge-offs	(215)	(441)	(758)	(2,819)
Recoveries	9	5	30	254
(Reversal of) provision for credit losses	451	(3,920)	2,792	(11,740)
Ending balance	49,122	43,860	49,122	43,860
Commercial Portfolio Segment | Multi-family mortgage
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	27,498	25,795	25,321	28,450
Charge-offs	(4)	0	(399)	(104)
Recoveries	0	0	0	0
(Reversal of) provision for credit losses	(322)	(1,568)	2,250	(4,119)
Ending balance	27,172	24,227	27,172	24,227
Commercial Portfolio Segment | Nonresidential mortgage
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	8,593	10,078	10,590	16,243
Charge-offs	(6)	(441)	(21)	(2,538)
Recoveries	0	0	0	0
(Reversal of) provision for credit losses	(343)	(598)	(2,325)	(4,666)
Ending balance	8,244	9,039	8,244	9,039
Commercial Portfolio Segment | Commercial business
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	1,819	1,903	1,792	2,086
Charge-offs	(205)	0	(338)	(175)
Recoveries	7	4	24	105
(Reversal of) provision for credit losses	108	(182)	251	(291)
Ending balance	1,729	1,725	1,729	1,725
Commercial Portfolio Segment | Construction
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	1,201	1,441	1,486	1,170
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
(Reversal of) provision for credit losses	115	(167)	(170)	104
Ending balance	1,316	1,274	1,316	1,274
Residential
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	9,355	8,601	7,540	9,747
Charge-offs	0	0	0	0
Recoveries	2	0	2	147
(Reversal of) provision for credit losses	908	(1,323)	2,723	(2,616)
Ending balance	10,265	7,278	10,265	7,278
Consumer Loans | Home equity loans
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	339	308	245	433
Charge-offs	0	0	0	0
Recoveries	0	0	0	1
(Reversal of) provision for credit losses	(12)	(72)	82	(198)
Ending balance	327	236	327	236
Consumer Loans | Other consumer
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	72	90	84	36
Charge-offs	0	0	0	(2)
Recoveries	0	1	4	1
(Reversal of) provision for credit losses	(3)	(10)	(19)	46
Ending balance	$ 69	$ 81	$ 69	$ 81