LOANS RECEIVABLE - Contractual Payment Status of Loans Receivable (Detail) - USD ($) $ in Thousands	Mar. 31, 2023	Jun. 30, 2022
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, before allowance for credit loss, fee and loan in process	$ 5,976,368	$ 5,436,576
Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, before allowance for credit loss, fee and loan in process	28,220	41,756
30-59 days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, before allowance for credit loss, fee and loan in process	6,893	8,825
60-89 days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, before allowance for credit loss, fee and loan in process	4,792	3,401
90 days and over
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, before allowance for credit loss, fee and loan in process	16,535	29,530
Not Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, before allowance for credit loss, fee and loan in process	5,948,148	5,394,820
Commercial Portfolio Segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, before allowance for credit loss, fee and loan in process	4,216,057	3,745,866
Commercial Portfolio Segment | Multi-family mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, before allowance for credit loss, fee and loan in process	2,835,852	2,409,090
Commercial Portfolio Segment | Nonresidential mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, before allowance for credit loss, fee and loan in process	1,002,643	1,019,838
Commercial Portfolio Segment | Commercial business
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, before allowance for credit loss, fee and loan in process	162,038	176,807
Commercial Portfolio Segment | Construction
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, before allowance for credit loss, fee and loan in process	215,524	140,131
Commercial Portfolio Segment | Past Due | Multi-family mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, before allowance for credit loss, fee and loan in process	11,599	13,992
Commercial Portfolio Segment | Past Due | Nonresidential mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, before allowance for credit loss, fee and loan in process	9,511	22,158
Commercial Portfolio Segment | Past Due | Commercial business
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, before allowance for credit loss, fee and loan in process	264	310
Commercial Portfolio Segment | Past Due | Construction
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, before allowance for credit loss, fee and loan in process	0	0
Commercial Portfolio Segment | 30-59 days | Multi-family mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, before allowance for credit loss, fee and loan in process	0	3,148
Commercial Portfolio Segment | 30-59 days | Nonresidential mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, before allowance for credit loss, fee and loan in process	3,842	4,026
Commercial Portfolio Segment | 30-59 days | Commercial business
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, before allowance for credit loss, fee and loan in process	0	98
Commercial Portfolio Segment | 30-59 days | Construction
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, before allowance for credit loss, fee and loan in process	0	0
Commercial Portfolio Segment | 60-89 days | Multi-family mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, before allowance for credit loss, fee and loan in process	3,940	3,056
Commercial Portfolio Segment | 60-89 days | Nonresidential mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, before allowance for credit loss, fee and loan in process	0	0
Commercial Portfolio Segment | 60-89 days | Commercial business
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, before allowance for credit loss, fee and loan in process	0	57
Commercial Portfolio Segment | 60-89 days | Construction
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, before allowance for credit loss, fee and loan in process	0	0
Commercial Portfolio Segment | 90 days and over | Multi-family mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, before allowance for credit loss, fee and loan in process	7,659	7,788
Commercial Portfolio Segment | 90 days and over | Nonresidential mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, before allowance for credit loss, fee and loan in process	5,669	18,132
Commercial Portfolio Segment | 90 days and over | Commercial business
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, before allowance for credit loss, fee and loan in process	264	155
Commercial Portfolio Segment | 90 days and over | Construction
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, before allowance for credit loss, fee and loan in process	0	0
Commercial Portfolio Segment | Not Past Due | Multi-family mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, before allowance for credit loss, fee and loan in process	2,824,253	2,395,098
Commercial Portfolio Segment | Not Past Due | Nonresidential mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, before allowance for credit loss, fee and loan in process	993,132	997,680
Commercial Portfolio Segment | Not Past Due | Commercial business
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, before allowance for credit loss, fee and loan in process	161,774	176,497
Commercial Portfolio Segment | Not Past Due | Construction
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, before allowance for credit loss, fee and loan in process	215,524	140,131
Residential
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, before allowance for credit loss, fee and loan in process	1,713,343	1,645,816
Residential | Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, before allowance for credit loss, fee and loan in process	6,709	5,233
Residential | 30-59 days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, before allowance for credit loss, fee and loan in process	2,961	1,525
Residential | 60-89 days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, before allowance for credit loss, fee and loan in process	852	253
Residential | 90 days and over
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, before allowance for credit loss, fee and loan in process	2,896	3,455
Residential | Not Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, before allowance for credit loss, fee and loan in process	1,706,634	1,640,583
Consumer Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, before allowance for credit loss, fee and loan in process	46,968	44,894
Consumer Loans | Home equity loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, before allowance for credit loss, fee and loan in process	44,376	42,028
Consumer Loans | Other consumer
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, before allowance for credit loss, fee and loan in process	2,592	2,866
Consumer Loans | Past Due | Home equity loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, before allowance for credit loss, fee and loan in process	98	63
Consumer Loans | Past Due | Other consumer
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, before allowance for credit loss, fee and loan in process	39	0
Consumer Loans | 30-59 days | Home equity loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, before allowance for credit loss, fee and loan in process	51	28
Consumer Loans | 30-59 days | Other consumer
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, before allowance for credit loss, fee and loan in process	39	0
Consumer Loans | 60-89 days | Home equity loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, before allowance for credit loss, fee and loan in process	0	35
Consumer Loans | 60-89 days | Other consumer
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, before allowance for credit loss, fee and loan in process	0	0
Consumer Loans | 90 days and over | Home equity loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, before allowance for credit loss, fee and loan in process	47	0
Consumer Loans | 90 days and over | Other consumer
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, before allowance for credit loss, fee and loan in process	0	0
Consumer Loans | Not Past Due | Home equity loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, before allowance for credit loss, fee and loan in process	44,278	41,965
Consumer Loans | Not Past Due | Other consumer
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, before allowance for credit loss, fee and loan in process	$ 2,553	$ 2,866