Loans - Narrative (Details)		3 Months Ended	9 Months Ended
	Jan. 06, 2022 USD ($)	Sep. 30, 2023 USD ($) loan	Sep. 30, 2023 USD ($) contract loan	Sep. 30, 2022 contract	Dec. 31, 2022 USD ($) loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accrued interest receivable on loans		$ 28,000,000	$ 28,000,000		$ 24,500,000
Net deferred loan fees		(1,600,000)	(1,600,000)		2,100,000
Overdraft balances included in home equity and consumer loans		557,000	557,000		1,300,000
Loans pledged for actual and potential borrowings at the Federal Home Loan Bank		$ 4,290,000,000	$ 4,290,000,000		$ 2,890,000,000
Number of loans still accruing | loan		0	0		0
Net PCD loans	$ 124,431,000
Financing receivable, excluding accrued interest, modified in period, amount		$ 0	$ 0
Financing receivable, accrual, troubled debt restructuring					$ 2,600,000
Financing receivable, troubled debt restructuring, subsequent default, number of contracts | contract			0	0
Residential And Consumer Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, nonaccrual, in the process of foreclosure		$ 392,000	$ 392,000		$ 898,000