Receivable and Allowance for Credit Losses - Narrative (Details)	12 Months Ended
	Dec. 31, 2023 USD ($) loan segment	Dec. 31, 2022 USD ($) loan	Dec. 31, 2021 USD ($) loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held-for-sale	$ 0	$ 0
Gain on sale of loans held-for-sale	2,300,000	242,000	$ 8,600,000
Loss on sale of loans held-for-sale	1,000,000	64,000	24,000
Purchases and grants of loans receivable	14,729,000	8,315,000	85,382,000
Loans receivable	7,874,537,000	7,677,564,000
Carrying value of servicing liability	551,000,000	497,100,000
Servicing income	$ 1,400,000	1,300,000	1,500,000
Threshold period, past due status of financing receivables	30 days
Threshold period, past due for nonperforming status of financing receivables	90 days
Non-accrual loans	$ 12,600,000	6,700,000
Increase in interest income if non-accrual had performed in line with their original terms	909,000	392,000	190,000
Cash basis interest income on non-accrual loans	358,000	161,000	242,000
Loans past due	0	0
Property acquired through foreclosure	$ 0	$ 0
Number of loans in the process of foreclosure | loan		2
Loans in process of foreclosure		$ 81,000
Number of loan portfolio segments | segment	7
Financing Receivable, Accrued Interest, after Allowance for Credit Loss, Statement of Financial Position [Extensible Enumeration]	Accrued interest receivable
Accrued interest receivable on loans receivable	$ 32,900,000	29,400,000
Specific allowance for loan losses attributable to impaired loans	614,000	339,000
Impaired loans for which there are no related allowance for loan losses	19,919,000	16,557,000
Stewardship Financial Corporation | Financial Asset Acquired with Credit Deterioration
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	1,700,000	2,000,000
Roselle Entities | Financial Asset Acquired with Credit Deterioration
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	0
Freehold Entities | Financial Asset Acquired with Credit Deterioration
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	2,800,000	3,700,000
RSI Entities
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, purchased with credit deterioration, allowance for credit loss at acquisition date	633,000
RSI Entities | Financial Asset Acquired with Credit Deterioration
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	10,600,000	11,300,000
Roselle Bank | Financial Asset Acquired with Credit Deterioration
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable		184,000
Less Than 90 Days
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	$ 1,600,000	$ 1,200,000
Number of loans in non-accrual status | loan	10	7
Related Parties
Accounts, Notes, Loans and Financing Receivable [Line Items]
Purchases and grants of loans receivable	$ 100,000	$ 751,000	$ 522,700
Loans receivable	$ 9,100,000	$ 9,300,000
Number of loans granted to related party | loan	1	2	1
Freddie Mac
Accounts, Notes, Loans and Financing Receivable [Line Items]
Proceeds from sales of loans receivable	$ 0	$ 0	$ 99,600,000
Gain on sale of loans receivable			2,300,000
Loss on sale of loans receivable			0
Real estate loans | One-to-four family
Accounts, Notes, Loans and Financing Receivable [Line Items]
Proceeds from sales of loans held-for-sale	73,400,000	2,700,000	18,500,000
Purchases and grants of loans receivable		8,300,000	11,800,000
Specific allowance for loan losses attributable to impaired loans	186,000	201,000
Impaired loans for which there are no related allowance for loan losses	1,170,000	1,296,000
Real estate loans | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Proceeds from sales of loans held-for-sale	18,400,000	2,800,000	6,400,000
Real estate loans | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Proceeds from sales of loans held-for-sale	21,400,000		19,100,000
Purchases and grants of loans receivable	14,700,000		73,600,000
Specific allowance for loan losses attributable to impaired loans	237,000	99,000
Impaired loans for which there are no related allowance for loan losses	12,741,000	14,836,000
Commercial business loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Proceeds from sales of loans held-for-sale	8,100,000	4,100,000	$ 258,100,000
Specific allowance for loan losses attributable to impaired loans	154,000	10,000
Impaired loans for which there are no related allowance for loan losses	5,814,000	143,000
Commercial business loans | Paycheck Protection Program
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	809,000	1,600,000
Financing receivable, unamortized loan cost (fee)	$ 0	(13,000)
Consumer loans | Home equity loans and advances
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loans in the process of foreclosure | loan	1
Loans in process of foreclosure	$ 93,000
Specific allowance for loan losses attributable to impaired loans	30,000	26,000
Impaired loans for which there are no related allowance for loan losses	$ 145,000	$ 223,000
Consumer loans | Mortgages
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loans in the process of foreclosure | loan	1
Loans in process of foreclosure	$ 576,000