Loans Receivable - Contractual Payment 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
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
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
Not Past Due [Member] | Home Equity Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	41,965	47,828
Not Past Due [Member] | One-to Four-Family Residential Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	1,640,583	1,439,501
Not Past Due [Member] | Commercial Business [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	176,497	168,550
Not Past Due [Member] | Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	140,131	93,804
Not Past Due [Member] | Other Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	2,866	3,258
Not Past Due [Member] | Non-Residential Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	997,680	1,046,553
Multi-Family Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans and Leases Receivable, Gross	2,409,090	2,039,260
Multi-Family Mortgage [Member] | Not Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	2,395,098	2,023,166
Past Due Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	41,756	57,650
Loans and Leases Receivable, Gross	5,436,576	4,880,310
Past Due Loans [Member] | Home Equity Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	63	43
Loans and Leases Receivable, Gross	42,028	47,871
Past Due Loans [Member] | One-to Four-Family Residential Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	5,233	8,220
Loans and Leases Receivable, Gross	1,645,816	1,447,721
Past Due Loans [Member] | Commercial Business [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	310	401
Loans and Leases Receivable, Gross	176,807	168,951
Past Due Loans [Member] | Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans and Leases Receivable, Gross	140,131	93,804
Past Due Loans [Member] | Other Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due		1
Loans and Leases Receivable, Gross	2,866	3,259
Past Due Loans [Member] | Non-Residential Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	22,158	32,891
Loans and Leases Receivable, Gross	1,019,838	1,079,444
Past Due Loans [Member] | Not Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	5,394,820	4,822,660
Past Due Loans [Member] | 30-59 days [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	8,825	389
Past Due Loans [Member] | 30-59 days [Member] | Home Equity Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	28	6
Past Due Loans [Member] | 30-59 days [Member] | One-to Four-Family Residential Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	1,525	382
Past Due Loans [Member] | 30-59 days [Member] | Commercial Business [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	98
Past Due Loans [Member] | 30-59 days [Member] | Other Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due		1
Past Due Loans [Member] | 30-59 days [Member] | Non-Residential Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	4,026
Past Due Loans [Member] | 60-89 days [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	3,401	2,739
Past Due Loans [Member] | 60-89 days [Member] | Home Equity Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	35	5
Past Due Loans [Member] | 60-89 days [Member] | One-to Four-Family Residential Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	253	2,734
Past Due Loans [Member] | 60-89 days [Member] | Commercial Business [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	57
Past Due Loans [Member] | 90 days and over [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	29,530	54,522
Past Due Loans [Member] | 90 days and over [Member] | Home Equity Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due		32
Past Due Loans [Member] | 90 days and over [Member] | One-to Four-Family Residential Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	3,455	5,104
Past Due Loans [Member] | 90 days and over [Member] | Commercial Business [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	155	401
Past Due Loans [Member] | 90 days and over [Member] | Non-Residential Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	18,132	32,891
Past Due Loans [Member] | Multi-Family Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	13,992	16,094
Loans and Leases Receivable, Gross	2,409,090	2,039,260
Past Due Loans [Member] | Multi-Family Mortgage [Member] | 30-59 days [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	3,148
Past Due Loans [Member] | Multi-Family Mortgage [Member] | 60-89 days [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	3,056
Past Due Loans [Member] | Multi-Family Mortgage [Member] | 90 days and over [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	$ 7,788	$ 16,094