LOANS, Allowance for Loan Losses (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Allowance for loan losses [Roll Forward]
Beginning balance	$ 49,310	$ 49,618	$ 49,284	$ 47,583
Charge-offs	(3,230)	(3,267)	(10,002)	(10,636)
Recoveries	1,592	1,567	4,568	4,844
Provision	1,751	2,215	5,573	8,342
Ending balance	49,423	50,133	49,423	50,133
Acquired Impaired [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	155	33	33	147
Charge-offs	0	0	0	(368)
Recoveries	0	0	0	0
Provision	1	15	123	269
Ending balance	156	48	156	48
Residential Portfolio Segment [Member] \| Business Lending [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	17,769	18,439	18,522	17,257
Charge-offs	(305)	(73)	(1,774)	(2,000)
Recoveries	290	93	593	404
Provision	301	321	714	3,119
Ending balance	18,055	18,780	18,055	18,780
Commercial Portfolio Segment [Member] \| Consumer Mortgage [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	10,763	10,473	10,124	10,465
Charge-offs	(200)	(144)	(1,040)	(588)
Recoveries	8	46	44	109
Provision	(94)	(205)	1,349	184
Ending balance	10,477	10,170	10,477	10,170
Consumer Portfolio Segment [Member] \| Consumer Indirect [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	14,345	14,424	14,366	13,468
Charge-offs	(2,224)	(2,364)	(5,529)	(6,031)
Recoveries	1,095	1,190	3,296	3,688
Provision	1,221	1,719	2,304	3,844
Ending balance	14,437	14,969	14,437	14,969
Consumer Portfolio Segment [Member] \| Consumer Direct [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	3,184	3,164	3,095	3,039
Charge-offs	(456)	(465)	(1,436)	(1,324)
Recoveries	167	223	567	612
Provision	383	299	1,052	894
Ending balance	3,278	3,221	3,278	3,221
Consumer Portfolio Segment [Member] \| Home Equity [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	2,103	2,015	2,144	2,107
Charge-offs	(45)	(221)	(223)	(325)
Recoveries	32	15	68	31
Provision	(8)	225	93	221
Ending balance	2,082	2,034	2,082	2,034
Unallocated Financing Receivables [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	991	1,070	1,000	1,100
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Provision	(53)	(159)	(62)	(189)
Ending balance	$ 938	$ 911	$ 938	$ 911

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

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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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