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LOANS - Carrying Amounts of Loans Purchased and Sold (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2021 USD ($)
Carrying Amounts of Loans Purchased and Sold
Purchases	$ 0
Sales	8,284
Commercial Portfolio Segment [Member] | Business Lending [Member]
Carrying Amounts of Loans Purchased and Sold
Purchases	0
Sales	0
Residential Portfolio Segment [Member] | Consumer Mortgage [Member]
Carrying Amounts of Loans Purchased and Sold
Purchases	0
Sales	8,284
Consumer Portfolio Segment [Member] | Consumer Indirect [Member]
Carrying Amounts of Loans Purchased and Sold
Purchases	0
Sales	0
Consumer Portfolio Segment [Member] | Consumer Direct [Member]
Carrying Amounts of Loans Purchased and Sold
Purchases	0
Sales	0
Consumer Portfolio Segment [Member] | Home Equity [Member]
Carrying Amounts of Loans Purchased and Sold
Purchases	0
Sales	$ 0

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- References

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- Definition

Amount of increase from purchase of financing receivable.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 11
-Subparagraph (h)
-URI http://asc.fasb.org/extlink&oid=121599337&loc=SL82919244-210447

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (e)
-URI http://asc.fasb.org/extlink&oid=121611835&loc=SL6953423-111524

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- Definition

Amount of decrease from sale and reclassification to held-for-sale of financing receivable.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 11
-Subparagraph (i)
-URI http://asc.fasb.org/extlink&oid=121599337&loc=SL82919244-210447

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-Publisher FASB
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-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (f)
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