LOANS - Pledged, Purchased credit impaired, Accretable yield (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Collateral value of pledged loans to Federal Reserve Bank of Boston	$ 71,900
Collateral value of pledged loans for FHLB borrowings	910,500
Total loans	2,562,885	$ 2,634,593
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield Movement Schedule
Balance at beginning of period	7,367	4,377
Acquisitions		4,391
Net reclassifications from (to) nonaccretable difference	1,146	541
Accretion	(2,957)	(1,942)
Balance at end of period	5,556	7,367
Acquired Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	598,131	$ 805,862
Acquired Loans \| Financial Asset Acquired with Credit Deterioration [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	12,700
Total notes balances	16,300
Acquired Loans \| Financial Asset Acquired and No Credit Deterioration [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	$ 585,400

Pledged Assets Separately Reported Loans Pledged for Federal Reserve Bank At Fair Value.

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- Definition

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.

+ References

No definition available.

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- Definition

Amount of the excess of a loan's cash flows expected to be collected over the investor's initial investment in acquired loans not accounted for as debt securities with evidence of deterioration of credit quality.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 30
-Section 15
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- Definition

Amount of accretion recognized for the excess of a loan's cash flows expected to be collected over the investor's initial investment in acquired loans not accounted for as debt securities, with evidence of deterioration of credit quality.

+ References

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- Definition

Amount of additions to the excess of a loan's cash flows expected to be collected over the investor's initial investment in acquired loans not accounted for as debt securities with evidence of deterioration of credit quality.

+ References

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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

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- Definition

Amount of reclassification (to) from nonaccretable difference (from) to the excess of a loan's cash flows expected to be collected over the investor's initial investment in acquired loans not accounted for as debt securities with evidence of deterioration of credit quality.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition

Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

+ References

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- Definition

Amount before allowance and after deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition

The fair value, as of the date of each statement of financial position presented, of loans that are restricted as collateral for the payment of the FHLB debt obligations, and that are reclassified and separately reported in the statement of financial position because the transferee has the right by contract or custom to sell or re-pledge them.

+ References

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