Loans - Non-Accrual at Amortized Cost (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2024	Dec. 31, 2023
Financing Receivable, Excluding Accrued Interest, Nonaccrual
Non-accrual amortized cost beginning of the reporting period	$ 23,659	$ 29,942
Non-accrual amortized cost end of the reporting period	24,983	23,659
Non-accrual with no related allowance	16,309	15,133
Interest income recognized	3	25
Loans ninety days or more past due and still accruing		1,463
Multi-family Residential Portfolio Segment [Member]
Financing Receivable, Excluding Accrued Interest, Nonaccrual
Non-accrual amortized cost beginning of the reporting period	3,640	3,547
Non-accrual amortized cost end of the reporting period	5,103	3,640
Non-accrual with no related allowance	5,103	3,640
Interest income recognized		2
Loans ninety days or more past due and still accruing		1,463
Commercial Real Estate [Member]
Financing Receivable, Excluding Accrued Interest, Nonaccrual
Non-accrual amortized cost beginning of the reporting period		254
One-To-Four Family - Mixed-Use Property Portfolio Segment [Member]
Financing Receivable, Excluding Accrued Interest, Nonaccrual
Non-accrual amortized cost beginning of the reporting period	1,005	1,045
Non-accrual amortized cost end of the reporting period	933	1,005
Non-accrual with no related allowance	933	1,005
Interest income recognized	1	3
One-To-Four Family - Residential Portfolio Segment [Member]
Financing Receivable, Excluding Accrued Interest, Nonaccrual
Non-accrual amortized cost beginning of the reporting period	4,670	3,953
Non-accrual amortized cost end of the reporting period	3,341	4,670
Non-accrual with no related allowance	3,341	4,670
Interest income recognized	1	3
Small Business Administration Portfolio Segment [Member]
Financing Receivable, Excluding Accrued Interest, Nonaccrual
Non-accrual amortized cost beginning of the reporting period	2,576	950
Non-accrual amortized cost end of the reporting period	2,641	2,576
Non-accrual with no related allowance	2,641	2,576
Commercial Business and Other Portfolio Segment [Member]
Financing Receivable, Excluding Accrued Interest, Nonaccrual
Non-accrual amortized cost beginning of the reporting period	11,768	20,193
Non-accrual amortized cost end of the reporting period	12,965	11,768
Non-accrual with no related allowance	4,291	3,242
Interest income recognized	$ 1	$ 17