Loans Receivable - Contractual Payment Status of Loans Receivable (Detail) - USD ($) $ in Thousands	Mar. 31, 2022	Jun. 30, 2021
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans and Leases Receivable, Gross	$ 5,024,915	$ 4,880,310
Home Equity Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans and Leases Receivable, Gross	41,501	47,871
One-to Four-Family Residential Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans and Leases Receivable, Gross	1,527,980	1,447,721
Commercial Business [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans and Leases Receivable, Gross	169,551	168,951
Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans and Leases Receivable, Gross	121,137	93,804
Residential Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans and Leases Receivable, Gross	1,527,980	1,447,721
Other Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans and Leases Receivable, Gross	2,755	3,259
Non-Residential Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans and Leases Receivable, Gross	1,085,988	1,079,444
Not Past Due [Member] | Home Equity Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	41,413	47,828
Not Past Due [Member] | One-to Four-Family Residential Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	1,521,082	1,439,501
Not Past Due [Member] | Commercial Business [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	169,206	168,550
Not Past Due [Member] | Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	121,137	93,804
Not Past Due [Member] | Other Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	2,755	3,258
Not Past Due [Member] | Non-Residential Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	1,058,604	1,046,553
Multi-Family Mortgage Member
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans and Leases Receivable, Gross	2,076,003	2,039,260
Multi-Family Mortgage Member | Not Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	2,047,806	2,023,166
Past Due Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	62,912	57,650
Loans and Leases Receivable, Gross	5,024,915	4,880,310
Past Due Loans [Member] | Home Equity Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	88	43
Loans and Leases Receivable, Gross	41,501	47,871
Past Due Loans [Member] | One-to Four-Family Residential Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	6,898	8,220
Loans and Leases Receivable, Gross	1,527,980	1,447,721
Past Due Loans [Member] | Commercial Business [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	345	401
Loans and Leases Receivable, Gross	169,551	168,951
Past Due Loans [Member] | Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans and Leases Receivable, Gross	121,137	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	2,755	3,259
Past Due Loans [Member] | Non-Residential Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	27,384	32,891
Loans and Leases Receivable, Gross	1,085,988	1,079,444
Past Due Loans [Member] | Not Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	4,962,003	4,822,660
Past Due Loans [Member] | 30-59 days [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	5,536	389
Past Due Loans [Member] | 30-59 days [Member] | Home Equity Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	25	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	3,410	382
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	2,101
Past Due Loans [Member] | 60-89 days [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	588	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	4	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	520	2,734
Past Due Loans [Member] | 60-89 days [Member] | Commercial Business [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	64
Past Due Loans [Member] | 90 days and over [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	56,788	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	59	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	2,968	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	281	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	25,283	32,891
Past Due Loans [Member] | Multi-Family Mortgage Member
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	28,197	16,094
Loans and Leases Receivable, Gross	2,076,003	2,039,260
Past Due Loans [Member] | Multi-Family Mortgage Member | 90 days and over [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	$ 28,197	$ 16,094