Loans Receivable and Allowance for Credit Losses - Amortized Basis (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Financing Receivable, Troubled Debt Restructuring [Line Items]
Modified period amount			$ 17,844	$ 6,529
% of Total Class of Loans	0.05%	0.01%	0.09%	0.06%
Mortgage loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Modified period amount			$ 2,342	$ 1,508
% of Total Class of Loans	0.02%	0.02%	0.02%	0.02%
Mortgage loans | Commercial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Modified period amount			$ 1,045
% of Total Class of Loans	0.01%		0.01%
Mortgage loans | Multi-family
Financing Receivable, Troubled Debt Restructuring [Line Items]
Modified period amount			$ 1,297	$ 1,508
% of Total Class of Loans	0.04%	0.08%	0.04%	0.08%
Commercial loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Modified period amount			$ 15,502	$ 5,021
% of Total Class of Loans	0.14%		0.33%	0.21%
Term Extension
Financing Receivable, Troubled Debt Restructuring [Line Items]
Modified period amount	$ 0	$ 0	$ 0	$ 3,771
Term Extension | Mortgage loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Modified period amount	0	0	0	0
Term Extension | Mortgage loans | Commercial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Modified period amount	0		0
Term Extension | Mortgage loans | Multi-family
Financing Receivable, Troubled Debt Restructuring [Line Items]
Modified period amount	0	0	0	0
Term Extension | Commercial loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Modified period amount	0		0	3,771
Interest Rate Reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Modified period amount	8,085	0	8,085	0
Interest Rate Reduction | Mortgage loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Modified period amount	2,342	0	2,342	0
Interest Rate Reduction | Mortgage loans | Commercial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Modified period amount	1,045		1,045
Interest Rate Reduction | Mortgage loans | Multi-family
Financing Receivable, Troubled Debt Restructuring [Line Items]
Modified period amount	1,297	0	1,297	0
Interest Rate Reduction | Commercial loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Modified period amount	5,743		5,743	0
Interest Rate Reduction and Term Extension
Financing Receivable, Troubled Debt Restructuring [Line Items]
Modified period amount	962	1,508	9,759	2,758
Interest Rate Reduction and Term Extension | Mortgage loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Modified period amount	0	1,508	0	1,508
Interest Rate Reduction and Term Extension | Mortgage loans | Commercial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Modified period amount	0		0
Interest Rate Reduction and Term Extension | Mortgage loans | Multi-family
Financing Receivable, Troubled Debt Restructuring [Line Items]
Modified period amount	0	$ 1,508	0	1,508
Interest Rate Reduction and Term Extension | Commercial loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Modified period amount	$ 962		$ 9,759	$ 1,250