LOANS, Allowance for Loan Losses (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Allowance for loan losses [Roll Forward]
Beginning balance	$ 49,107	$ 48,103	$ 49,284	$ 47,583
Charge-offs	(2,871)	(2,622)	(6,772)	(7,369)
Recoveries	1,674	1,689	2,976	3,277
Provision	1,400	2,448	3,822	6,127
Ending balance	49,310	49,618	49,310	49,618
Acquired Impaired [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	155	308	33	147
Charge-offs	0	(323)	0	(367)
Recoveries	0	0	0	0
Provision	0	48	122	253
Ending balance	155	33	155	33
Residential Portfolio Segment [Member] \| Business Lending [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	18,271	17,607	18,522	17,257
Charge-offs	(253)	(260)	(1,469)	(1,928)
Recoveries	169	114	303	312
Provision	(418)	978	413	2,798
Ending balance	17,769	18,439	17,769	18,439
Commercial Portfolio Segment [Member] \| Consumer Mortgage [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	10,317	10,382	10,124	10,465
Charge-offs	(587)	(245)	(840)	(444)
Recoveries	14	54	36	62
Provision	1,019	282	1,443	390
Ending balance	10,763	10,473	10,763	10,473
Consumer Portfolio Segment [Member] \| Consumer Indirect [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	14,251	13,698	14,366	13,468
Charge-offs	(1,482)	(1,383)	(3,305)	(3,667)
Recoveries	1,239	1,347	2,201	2,498
Provision	337	762	1,083	2,125
Ending balance	14,345	14,424	14,345	14,424
Consumer Portfolio Segment [Member] \| Consumer Direct [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	3,056	2,984	3,095	3,039
Charge-offs	(445)	(364)	(980)	(860)
Recoveries	221	167	400	389
Provision	352	377	669	596
Ending balance	3,184	3,164	3,184	3,164
Consumer Portfolio Segment [Member] \| Home Equity [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	2,067	2,040	2,144	2,107
Charge-offs	(104)	(47)	(178)	(103)
Recoveries	31	7	36	16
Provision	109	15	101	(5)
Ending balance	2,103	2,015	2,103	2,015
Unallocated Financing Receivables [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	990	1,084	1,000	1,100
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Provision	1	(14)	(9)	(30)
Ending balance	$ 991	$ 1,070	$ 991	$ 1,070

Amount of recovery of loans and lease receivables which had previously been fully or partially written-off as bad debts.

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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

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- Definition

Amount of loans and leases that have been written off from both loan receivables and allowance reserve for credit loss.

+ References

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- Definition

Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

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Amount of expense related to estimated loss from loan and lease transactions.

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