Amount of allowance for credit loss at acquisition date of financing receivable purchased.

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Amount of loans purchased with credit deterioration during the period.

+ References

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The premium percentage on loans purchased.

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- Definition

Percentage of allowance for credit loss to total financing receivable outstanding.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name Regulation S-K (SK)
-Number 229
-Section 1405
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- Definition

Amount, after allowance for credit loss, of accrued interest on financing receivable.

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Indicates line item in statement of financial position that includes accrued interest, after allowance for credit loss, on financing receivable.

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Amount of allowance for credit loss on financing receivable. Excludes allowance for financing receivable covered under loss sharing agreement.

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Amount, excluding accrued interest, of allowance for credit loss at acquisition date of financing receivable purchased with credit deterioration. Excludes net investment in lease.

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The cash outflow for the purchase of loan receivable arising from the financing of goods and services.

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Allowance for Credit Losses and Credit Quality of Loans, Summary (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2024	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023	Dec. 31, 2022
Allowance for Credit Losses [Abstract]
Allowance for credit losses	$ 115,300	$ 115,300	$ 114,400
Percentage of allowance of credit losses	1.19%	1.19%	1.19%
Salisbury Bank [Member]
Allowance for Credit Losses [Abstract]
Loans purchased with credit deterioration	$ 0		$ 219,500
Allowance for credit losses on loans purchased			5,800
Allowance for credit losses at acquisition		$ 14,500
Salisbury Bank [Member] \| PCD [Member]
Allowance for Credit Losses [Abstract]
Allowance for credit losses at acquisition		5,800
Salisbury Bank [Member] \| Non-PCD [Member]
Allowance for Credit Losses [Abstract]
Allowance for credit losses at acquisition		8,800
ASU 2022-02 [Member]
Allowance for Credit Losses [Abstract]
Allowance for credit losses				$ 100,250	$ 100,152
Loans [Member] \| Cumulative Effect, Period of Adoption, Adjustment [Member] \| ASU 2022-02 [Member]
Allowance for Credit Losses [Abstract]
Allowance for credit losses					(600)
Accrued Interest Receivable [Member]
Allowance for Credit Losses [Abstract]
Allowance for credit losses	0	0	0
AIR on loans	$ 34,400	$ 34,400	$ 34,100
Financing Receivable, Accrued Interest, after Allowance for Credit Loss, Statement of Financial Position [Extensible Enumeration]	Other Assets	Other Assets	Other Assets
Residential [Member]
Allowance for Credit Losses [Abstract]
Allowance for credit losses	$ 23,409	$ 23,409	$ 22,070
Amount of loans purchased	$ 400		$ 3,800
Premium on loans purchased	7.00%		7.00%
Allowance for credit losses on loans purchased	$ 4		$ 31
Residential [Member] \| ASU 2022-02 [Member]
Allowance for Credit Losses [Abstract]
Allowance for credit losses				$ 15,390	$ 14,539