Consumer Credit Exposures Period Past Due Required To Classify Loans As Special Mention Maximum.

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Maximum exposure to credit risk of loans or receivables.

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Mortgage Loans In Process Of Foreclosure, Number

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Maximum potential amount of future undiscounted payments that could be required under the credit derivative, before reduction for potential recoveries under recourse or collateralization provisions.

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Represents the aggregate of total long-term debt, including current maturities and short-term debt.

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No definition available.

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Amount excluding accrued interest, of allowance for credit loss on financing receivable. Excludes net investment in lease.

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Amortized cost excluding accrued interest, after allowance for credit loss, of financing receivable. Excludes net investment in lease.

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Amount, excluding accrued interest, of decrease in allowance for credit loss on financing receivable from writeoff. Excludes net investment in lease.

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Amount, excluding accrued interest, of credit loss expense (reversal of expense) on financing receivable. Excludes net investment in lease.

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- Definition

Amortized cost excluding accrued interest, of financing receivable with payment default in current period and modified within previous 12 months preceding payment default for debtor experiencing financial difficulty.

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Amount excluding accrued interest, of increase in financing receivable from purchase. Excludes net investment in lease.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount of commitment to lend additional funds to debtor experiencing financial difficulty for which creditor has modified terms of financing receivable.

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Recorded investment of consumer mortgage loan receivables secured by residential real estate properties for which formal foreclosure proceedings are in process.

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The aggregate amount of the participating mortgage obligation at the end of the accounting period.

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Loans and Allowance for Credit Losses - Additional Information (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2024 USD ($) loan	Jun. 30, 2023 USD ($)	Jun. 30, 2024 USD ($) loan	Jun. 30, 2023 USD ($)	Mar. 31, 2024 USD ($)	Dec. 31, 2023 USD ($) loan	Mar. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)
Changes in lines of credit,resrticted to commercial exposure
Loan syndications, amount	$ 100,000,000		$ 100,000,000
Financing receivable, excluding accrued interest, after allowance for credit loss	13,953,773,000		13,953,773,000			$ 13,799,367,000
Debt, long-term and short-term, combined amount	48,940,000		48,940,000			48,216,000
Mortgage loans partially or wholly-owned by others and serviced by the Company	74,300,000		74,300,000			77,200,000
Loan purchases			0	$ 32,000,000.0
Provision for allowance for loan losses	6,126,000	$ 7,501,000	13,577,000	7,526,000
Partial charge off	1,692,000	845,000	9,707,000	1,756,000
Financing receivable, allowance for credit loss, excluding accrued interest	156,146,000	147,955,000	$ 156,146,000	147,955,000	$ 149,190,000	148,993,000	$ 140,938,000	$ 142,211,000
Maximum number of days required for special mention			90 days
Loans modified during the prior 12 months which had subsequently defaulted			$ 100,000	0
Financing receivable, modified, commitment to lend	300,000		300,000			0
Federal Home Loan Bank Advances \| Asset Pledged as Collateral
Changes in lines of credit,resrticted to commercial exposure
Financing receivable, excluding accrued interest, after allowance for credit loss	4,400,000,000		4,400,000,000			4,600,000,000
Federal Reserve Bank Advances \| Asset Pledged as Collateral
Changes in lines of credit,resrticted to commercial exposure
Financing receivable, excluding accrued interest, after allowance for credit loss	1,200,000,000		1,200,000,000			1,100,000,000
Residential Real Estate
Changes in lines of credit,resrticted to commercial exposure
Financing receivable, collateral dependent loans	1,500,000		1,500,000			800,000
Commercial Portfolio Segment
Changes in lines of credit,resrticted to commercial exposure
Financing receivable, collateral dependent loans	23,300,000		23,300,000			30,700,000
Unfunded Loan Commitment
Changes in lines of credit,resrticted to commercial exposure
Financing receivable, allowance for credit loss, excluding accrued interest	11,600,000		11,600,000			14,100,000
Residential real estate \| Residential Real Estate
Changes in lines of credit,resrticted to commercial exposure
Amortized cost of loans purchased	377,000,000.0		377,000,000.0			385,500,000
Provision for allowance for loan losses	(133,000)	(136,000)	(173,000)	(301,000)
Partial charge off	0	0	10,000	0
Financing receivable, allowance for credit loss, excluding accrued interest	$ 25,829,000	27,012,000	$ 25,829,000	27,012,000	25,935,000	$ 25,954,000	27,130,000	28,129,000
Number of loans in process of foreclosure \| loan	3		3			2
Mortgage loans in process of foreclosure, amount	$ 300,000		$ 300,000			$ 200,000
Consumer home equity \| Consumer Portfolio Segment
Changes in lines of credit,resrticted to commercial exposure
Provision for allowance for loan losses	38,000	(138,000)	129,000	(203,000)
Partial charge off	32,000	0	34,000	7,000
Financing receivable, allowance for credit loss, excluding accrued interest	$ 5,781,000	6,044,000	$ 5,781,000	6,044,000	5,684,000	$ 5,595,000	6,182,000	6,454,000
Number of loans in process of foreclosure \| loan	10		10			3
Mortgage loans in process of foreclosure, amount	$ 900,000		$ 900,000			$ 200,000
Commercial and industrial \| Commercial Portfolio Segment
Changes in lines of credit,resrticted to commercial exposure
Provision for allowance for loan losses	(3,000)	2,580,000	1,876,000	2,464,000
Partial charge off	0	0	0	0
Financing receivable, allowance for credit loss, excluding accrued interest	28,916,000	29,535,000	28,916,000	29,535,000	28,863,000	26,959,000	26,929,000	26,859,000
Commercial real estate \| Commercial Portfolio Segment
Changes in lines of credit,resrticted to commercial exposure
Provision for allowance for loan losses	2,439,000	4,329,000	8,711,000	4,788,000
Partial charge off	0	0	7,250,000	0
Financing receivable, allowance for credit loss, excluding accrued interest	69,079,000	$ 59,524,000	69,079,000	$ 59,524,000	$ 64,629,000	65,475,000	$ 55,193,000	$ 54,730,000
Federal Home Loan Bank Advances
Changes in lines of credit,resrticted to commercial exposure
Advance from Federal Home Loan Bank	17,400,000		17,400,000			17,700,000
Federal Reserve Bank Advances
Changes in lines of credit,resrticted to commercial exposure
Debt, long-term and short-term, combined amount	0		0			$ 0
Unrated \| Minimum
Changes in lines of credit,resrticted to commercial exposure
Lines of credit, exposure	100,000		100,000
Unrated \| Line of Credit \| Commercial Portfolio Segment \| Maximum
Changes in lines of credit,resrticted to commercial exposure
Lines of credit, exposure	1,500,000		1,500,000
Unrated \| Line of Credit \| Business Banking \| Commercial Portfolio Segment \| Maximum
Changes in lines of credit,resrticted to commercial exposure
Lines of credit, exposure	$ 1,500,000		$ 1,500,000