Loans Receivable - Performance Status of Loans Receivable (Detail) - USD ($) $ in Thousands	Jun. 30, 2022	Jun. 30, 2021
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans and leases receivable, Gross	$ 5,436,576	$ 4,880,310
Commercial Business [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans and leases receivable, Gross	176,807	168,951
Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans and leases receivable, Gross	140,131	93,804
Other Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans and leases receivable, Gross	2,866	3,259
Non-Residential Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans and leases receivable, Gross	1,019,838	1,079,444
Multi-Family Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans and leases receivable, Gross	2,409,090	2,039,260
Home Equity Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans and leases receivable, Gross	42,028	47,871
One-to Four-Family Residential Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans and leases receivable, Gross	1,645,816	1,447,721
Nonperforming Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans and leases receivable, Gross	5,436,576	4,880,310
Nonperforming Loans [Member] | Commercial Business [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans and leases receivable, Gross	176,807	168,951
Nonperforming Loans [Member] | Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans and leases receivable, Gross	140,131	93,804
Nonperforming Loans [Member] | Other Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans and leases receivable, Gross	2,866	3,259
Nonperforming Loans [Member] | Non-Residential Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans and leases receivable, Gross	1,019,838	1,079,444
Nonperforming Loans [Member] | Multi-Family Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans and leases receivable, Gross	2,409,090	2,039,260
Nonperforming Loans [Member] | Home Equity Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans and leases receivable, Gross	42,028	47,871
Nonperforming Loans [Member] | One-to Four-Family Residential Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans and leases receivable, Gross	1,645,816	1,447,721
Nonperforming Loans [Member] | Performing Financing Receivable [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans and leases receivable, Gross	5,366,255	4,800,543
Nonperforming Loans [Member] | Performing Financing Receivable [Member] | Commercial Business [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans and leases receivable, Gross	176,514	168,039
Nonperforming Loans [Member] | Performing Financing Receivable [Member] | Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans and leases receivable, Gross	138,570	91,576
Nonperforming Loans [Member] | Performing Financing Receivable [Member] | Other Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans and leases receivable, Gross	2,866	3,259
Nonperforming Loans [Member] | Performing Financing Receivable [Member] | Non-Residential Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans and leases receivable, Gross	987,944	1,042,257
Nonperforming Loans [Member] | Performing Financing Receivable [Member] | Multi-Family Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans and leases receivable, Gross	2,382,437	2,020,734
Nonperforming Loans [Member] | Performing Financing Receivable [Member] | Home Equity Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans and leases receivable, Gross	40,597	46,127
Nonperforming Loans [Member] | Performing Financing Receivable [Member] | One-to Four-Family Residential Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans and leases receivable, Gross	1,637,327	1,428,551
Nonperforming Loans [Member] | Nonperforming Financing Receivable [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	25,026	29,022
Nonaccrual loans with no allowance for credit losses	45,295	50,745
Total nonperforming	70,321	79,767
Nonperforming Loans [Member] | Nonperforming Financing Receivable [Member] | Commercial Business [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	212	236
Nonaccrual loans with no allowance for credit losses	81	676
Total nonperforming	293	912
Nonperforming Loans [Member] | Nonperforming Financing Receivable [Member] | Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	0
Nonaccrual loans with no allowance for credit losses	1,561	2,228
Total nonperforming	1,561	2,228
Nonperforming Loans [Member] | Nonperforming Financing Receivable [Member] | Non-Residential Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	12,602	12,612
Nonaccrual loans with no allowance for credit losses	19,292	24,575
Total nonperforming	31,894	37,187
Nonperforming Loans [Member] | Nonperforming Financing Receivable [Member] | Multi-Family Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	8,367	8,300
Nonaccrual loans with no allowance for credit losses	18,286	10,226
Total nonperforming	26,653	18,526
Nonperforming Loans [Member] | Nonperforming Financing Receivable [Member] | Home Equity Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	302	452
Nonaccrual loans with no allowance for credit losses	1,129	1,292
Total nonperforming	1,431	1,744
Nonperforming Loans [Member] | Nonperforming Financing Receivable [Member] | One-to Four-Family Residential Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	3,543	7,422
Nonaccrual loans with no allowance for credit losses	4,946	11,748
Total nonperforming	$ 8,489	$ 19,170