LOANS RECEIVABLE - Performance 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
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
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
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
Performing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, before allowance for credit loss, fee and loan in process	5,932,342	5,366,255
Performing | Residential
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, before allowance for credit loss, fee and loan in process	1,707,334	1,637,327
Nonperforming
Financing Receivable, Recorded Investment, Past Due [Line Items]
90 Days and Over Past Due Accruing	0	0
Nonaccrual Loans with Allowance for Credit Losses	19,210	25,026
Nonaccrual Loans with no Allowance for Credit Losses	24,816	45,295
Financing receivable, before allowance for credit loss, fee and loan in process	44,026	70,321
Nonperforming | Residential
Financing Receivable, Recorded Investment, Past Due [Line Items]
90 Days and Over Past Due Accruing	0	0
Nonaccrual Loans with Allowance for Credit Losses	1,025	3,543
Nonaccrual Loans with no Allowance for Credit Losses	4,984	4,946
Financing receivable, before allowance for credit loss, fee and loan in process	6,009	8,489
Multi-family mortgage | Commercial Portfolio Segment
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
Multi-family mortgage | Performing | Commercial Portfolio Segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, before allowance for credit loss, fee and loan in process	2,815,778	2,382,437
Multi-family mortgage | Nonperforming | Commercial Portfolio Segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
90 Days and Over Past Due Accruing	0	0
Nonaccrual Loans with Allowance for Credit Losses	5,762	8,367
Nonaccrual Loans with no Allowance for Credit Losses	14,312	18,286
Financing receivable, before allowance for credit loss, fee and loan in process	20,074	26,653
Nonresidential mortgage | Commercial Portfolio Segment
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
Nonresidential mortgage | Performing | Commercial Portfolio Segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, before allowance for credit loss, fee and loan in process	985,021	987,944
Nonresidential mortgage | Nonperforming | Commercial Portfolio Segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
90 Days and Over Past Due Accruing	0	0
Nonaccrual Loans with Allowance for Credit Losses	12,337	12,602
Nonaccrual Loans with no Allowance for Credit Losses	5,285	19,292
Financing receivable, before allowance for credit loss, fee and loan in process	17,622	31,894
Commercial business | Commercial Portfolio Segment
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 business | Performing | Commercial Portfolio Segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, before allowance for credit loss, fee and loan in process	161,767	176,514
Commercial business | Nonperforming | Commercial Portfolio Segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
90 Days and Over Past Due Accruing	0	0
Nonaccrual Loans with Allowance for Credit Losses	86	212
Nonaccrual Loans with no Allowance for Credit Losses	185	81
Financing receivable, before allowance for credit loss, fee and loan in process	271	293
Construction | Commercial Portfolio Segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, before allowance for credit loss, fee and loan in process	215,524	140,131
Construction | Performing | Commercial Portfolio Segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, before allowance for credit loss, fee and loan in process	215,524	138,570
Construction | Nonperforming | Commercial Portfolio Segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
90 Days and Over Past Due Accruing	0	0
Nonaccrual Loans with Allowance for Credit Losses	0	0
Nonaccrual Loans with no Allowance for Credit Losses	0	1,561
Financing receivable, before allowance for credit loss, fee and loan in process	0	1,561
Home equity loans | Consumer 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
Home equity loans | Performing | Consumer Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, before allowance for credit loss, fee and loan in process	44,326	40,597
Home equity loans | Nonperforming | Consumer Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
90 Days and Over Past Due Accruing	0	0
Nonaccrual Loans with Allowance for Credit Losses	0	302
Nonaccrual Loans with no Allowance for Credit Losses	50	1,129
Financing receivable, before allowance for credit loss, fee and loan in process	50	1,431
Other consumer | Consumer Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, before allowance for credit loss, fee and loan in process	2,592	2,866
Other consumer | Performing | Consumer Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivable, before allowance for credit loss, fee and loan in process	2,592	2,866
Other consumer | Nonperforming | Consumer Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
90 Days and Over Past Due Accruing	0	0
Nonaccrual Loans with Allowance for Credit Losses	0	0
Nonaccrual Loans with no Allowance for Credit Losses	0	0
Financing receivable, before allowance for credit loss, fee and loan in process	$ 0	$ 0