Loans - Composition of Loans (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Loans:
Net unamortized premiums and unearned loan fees	$ 8,836	$ 9,011
Total loans, net of fees and costs excluding portfolio layer basis adjustments	6,839,050	6,934,769
Unallocated portfolio layer basis adjustments	(6,625)
Total loans, net of fees and costs	6,832,425	6,934,769
Multi-Family Residential
Loans:
Loans before allowance for credit losses, fee and costs	2,593,955	2,601,384
Commercial Real Estate
Loans:
Loans before allowance for credit losses, fee and costs	1,917,749	1,913,040
One-To-Four Family - Mixed Used Property
Loans:
Loans before allowance for credit losses, fee and costs	542,368	554,314
One-To-Four Family - Residential
Loans:
Loans before allowance for credit losses, fee and costs	230,055	241,246
Construction Portfolio Segment
Loans:
Loans before allowance for credit losses, fee and costs	57,325	70,951
Total loans, net of fees and costs excluding portfolio layer basis adjustments	57,205	70,824
Small Business Administration
Loans:
Loans before allowance for credit losses, fee and costs	22,404	23,275
Commercial Business and Other
Loans:
Loans before allowance for credit losses, fee and costs	$ 1,466,358	$ 1,521,548