Loans - Composition of Loans (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Loans:
Net unamortized premiums and unearned loan fees	$ 8,337	$ 9,590
Total loans, net of fees and costs excluding portfolio layer basis adjustments	6,828,277	6,907,899
Unallocated portfolio layer basis adjustments	(6,334)	(949)
Total loans, net of fees and costs	6,821,943	6,906,950
Multi-Family Residential
Loans:
Loans before allowance for credit losses, fee and costs	2,622,737	2,658,205
Commercial Real Estate
Loans:
Loans before allowance for credit losses, fee and costs	1,925,312	1,958,252
One-To-Four Family - Mixed Used Property
Loans:
Loans before allowance for credit losses, fee and costs	516,198	530,243
One-To-Four Family - Residential
Loans:
Loans before allowance for credit losses, fee and costs	267,156	220,213
Construction Portfolio Segment
Loans:
Loans before allowance for credit losses, fee and costs	60,568	58,673
Total loans, net of fees and costs excluding portfolio layer basis adjustments	60,141	58,261
Small Business Administration
Loans:
Loans before allowance for credit losses, fee and costs	16,244	20,205
Commercial Business and Other
Loans:
Loans before allowance for credit losses, fee and costs	$ 1,411,725	$ 1,452,518