Loans - Age Analysis of Recorded Investment in Loans (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Total	$ 6,760,393
Total loans	6,760,393	$ 6,638,105
Financing Receivables, 30 to 59 Days Past Due [Member]
Total	8,016	11,978
Financing Receivables, 60 to 89 Days Past Due [Member]
Total	2,071	4,457
Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Total	14,870	14,433
Total Past Due [Member]
Total	24,957	30,869
Current [Member]
Total	6,735,436	6,607,236
Multi-family Residential Portfolio Segment [Member]
Total	2,535,187
Total loans	2,535,187	2,519,227
Multi-family Residential Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Total	2,413	3,652
Multi-family Residential Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Total	0	4,193
Multi-family Residential Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Total	3,707	2,652
Multi-family Residential Portfolio Segment [Member] | Total Past Due [Member]
Total	6,120	10,497
Multi-family Residential Portfolio Segment [Member] | Current [Member]
Total	2,529,067	2,508,730
Commercial Real Estate
Total	1,866,383
Total loans	1,866,383	1,777,375
Commercial Real Estate | Financing Receivables, 30 to 59 Days Past Due [Member]
Total	337	5,743
Commercial Real Estate | Financing Receivables, 60 to 89 Days Past Due [Member]
Total	0	0
Commercial Real Estate | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Total	273	640
Commercial Real Estate | Total Past Due [Member]
Total	610	6,383
Commercial Real Estate | Current [Member]
Total	1,865,773	1,770,992
One-To-Four Family - Mixed-Use Property Portfolio Segment [Member]
Total	564,133
Total loans	564,133	574,936
One-To-Four Family - Mixed-Use Property Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Total	3,937	2,319
One-To-Four Family - Mixed-Use Property Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Total	0	0
One-To-Four Family - Mixed-Use Property Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Total	795	1,321
One-To-Four Family - Mixed-Use Property Portfolio Segment [Member] | Total Past Due [Member]
Total	4,732	3,640
One-To-Four Family - Mixed-Use Property Portfolio Segment [Member] | Current [Member]
Total	559,401	571,296
One-To-Four Family - Residential Portfolio Segment [Member]
Total	252,109
Total loans	252,109	277,812
One-To-Four Family - Residential Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Total	1,196	163
One-To-Four Family - Residential Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Total	77	224
One-To-Four Family - Residential Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Total	4,708	7,482
One-To-Four Family - Residential Portfolio Segment [Member] | Total Past Due [Member]
Total	5,981	7,870
One-To-Four Family - Residential Portfolio Segment [Member] | Current [Member]
Total	246,128	269,942
Construction Portfolio Segment [Member]
Total	71,961
Total loans	71,961	59,473
Construction Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Total	0	0
Construction Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Total	0	0
Construction Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Total	856	0
Construction Portfolio Segment [Member] | Total Past Due [Member]
Total	856	0
Construction Portfolio Segment [Member] | Current [Member]
Total	71,105	59,473
Small Business Administration Portfolio Segment [Member]
Total	40,011
Total loans	40,011	91,836
Small Business Administration Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Total	40	0
Small Business Administration Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Total	1,991	0
Small Business Administration Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Total	951	952
Small Business Administration Portfolio Segment [Member] | Total Past Due [Member]
Total	2,982	952
Small Business Administration Portfolio Segment [Member] | Current [Member]
Total	37,029	90,884
Commercial Business and Other Portfolio Segment [Member]
Total loans	1,430,609	1,337,446
Commercial Business and Other Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Total	93	101
Commercial Business and Other Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Total	3	40
Commercial Business and Other Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Total	3,580	1,386
Commercial Business and Other Portfolio Segment [Member] | Total Past Due [Member]
Total	3,676	1,527
Commercial Business and Other Portfolio Segment [Member] | Current [Member]
Total	$ 1,426,933	$ 1,335,919