Loans - Age Analysis of Recorded Investment in Loans (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Total	$ 6,904,176
Loans, net of fees and costs	6,904,176	$ 6,934,769
Financing Receivables, 30 to 59 Days Past Due [Member]
Total	8,583	18,456
Financing Receivables, 60 to 89 Days Past Due [Member]
Total	2,327	1,803
Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Total	17,946	22,425
Total Past Due [Member]
Total	28,856	42,684
Current [Member]
Total	6,875,320	6,892,085
Multi-family Residential Portfolio Segment [Member]
Total	2,604,174
Loans, net of fees and costs	2,604,174	2,605,172
Multi-family Residential Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Total	3,464	1,475
Multi-family Residential Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Total	0	1,787
Multi-family Residential Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Total	3,975	3,547
Multi-family Residential Portfolio Segment [Member] | Total Past Due [Member]
Total	7,439	6,809
Multi-family Residential Portfolio Segment [Member] | Current [Member]
Total	2,596,735	2,598,363
Commercial Real Estate [Member]
Total	1,905,707
Loans, net of fees and costs	1,905,707	1,914,898
Commercial Real Estate [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Total	0	2,561
Commercial Real Estate [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Total	179	0
Commercial Real Estate [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Total	0	254
Commercial Real Estate [Member] | Total Past Due [Member]
Total	179	2,815
Commercial Real Estate [Member] | Current [Member]
Total	1,905,528	1,912,083
One-To-Four Family - Mixed-Use Property Portfolio Segment [Member]
Total	551,971
Loans, net of fees and costs	551,971	557,295
One-To-Four Family - Mixed-Use Property Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Total	2,562	3,721
One-To-Four Family - Mixed-Use Property Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Total	381	0
One-To-Four Family - Mixed-Use Property Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Total	797	797
One-To-Four Family - Mixed-Use Property Portfolio Segment [Member] | Total Past Due [Member]
Total	3,740	4,518
One-To-Four Family - Mixed-Use Property Portfolio Segment [Member] | Current [Member]
Total	548,231	552,777
One-To-Four Family - Residential Portfolio Segment [Member]
Total	239,585
Loans, net of fees and costs	239,585	242,480
One-To-Four Family - Residential Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Total	2,382	2,734
One-To-Four Family - Residential Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Total	68	0
One-To-Four Family - Residential Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Total	4,396	3,953
One-To-Four Family - Residential Portfolio Segment [Member] | Total Past Due [Member]
Total	6,846	6,687
One-To-Four Family - Residential Portfolio Segment [Member] | Current [Member]
Total	232,739	235,793
Construction Portfolio Segment
Total	60,373
Loans, net of fees and costs	60,373	70,824
Construction Portfolio Segment | Financing Receivables, 30 to 59 Days Past Due [Member]
Total	0	0
Construction Portfolio Segment | Financing Receivables, 60 to 89 Days Past Due [Member]
Total	0	0
Construction Portfolio Segment | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Total	0	2,600
Construction Portfolio Segment | Total Past Due [Member]
Total	0	2,600
Construction Portfolio Segment | Current [Member]
Total	60,373	68,224
Small Business Administration Portfolio Segment [Member]
Total	22,760
Loans, net of fees and costs	22,760	23,193
Small Business Administration Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Total	142	329
Small Business Administration Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Total	1,679	0
Small Business Administration Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Total	949	950
Small Business Administration Portfolio Segment [Member] | Total Past Due [Member]
Total	2,770	1,279
Small Business Administration Portfolio Segment [Member] | Current [Member]
Total	19,990	21,914
Commercial Business and Other Portfolio Segment [Member]
Loans, net of fees and costs	1,519,606	1,520,907
Commercial Business and Other Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Total	33	7,636
Commercial Business and Other Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Total	20	16
Commercial Business and Other Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Total	7,829	10,324
Commercial Business and Other Portfolio Segment [Member] | Total Past Due [Member]
Total	7,882	17,976
Commercial Business and Other Portfolio Segment [Member] | Current [Member]
Total	$ 1,511,724	$ 1,502,931