LOANS AND LEASES (Class and Credit Indicator) (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Recorded investment in the loans and leases, by class and credit indicator
Loans and leases, gross	$ 4,244,509	$ 4,075,873
Net deferred costs	2,604	2,493
Total loans and leases, net of deferred costs	4,247,113	4,078,366
Commercial, Financial & Agricultural
Recorded investment in the loans and leases, by class and credit indicator
Loans and leases, gross	590,071	581,177
Net deferred costs	412	483
Total loans and leases, net of deferred costs	590,483	581,660
Leases
Recorded investment in the loans and leases, by class and credit indicator
Loans and leases, gross	52	124
Net deferred costs	0	0
Total loans and leases, net of deferred costs	52	124
Pass
Recorded investment in the loans and leases, by class and credit indicator
Loans and leases, gross	4,187,362	4,032,344
Pass | Commercial, Financial & Agricultural
Recorded investment in the loans and leases, by class and credit indicator
Loans and leases, gross	574,264	552,706
Pass | Leases
Recorded investment in the loans and leases, by class and credit indicator
Loans and leases, gross	52	124
Special Mention
Recorded investment in the loans and leases, by class and credit indicator
Loans and leases, gross	30,705	18,373
Special Mention | Commercial, Financial & Agricultural
Recorded investment in the loans and leases, by class and credit indicator
Loans and leases, gross	3,994	7,961
Special Mention | Leases
Recorded investment in the loans and leases, by class and credit indicator
Loans and leases, gross	0	0
Substandard
Recorded investment in the loans and leases, by class and credit indicator
Loans and leases, gross	26,354	24,998
Substandard | Commercial, Financial & Agricultural
Recorded investment in the loans and leases, by class and credit indicator
Loans and leases, gross	11,813	20,510
Substandard | Leases
Recorded investment in the loans and leases, by class and credit indicator
Loans and leases, gross	0	0
Loss
Recorded investment in the loans and leases, by class and credit indicator
Loans and leases, gross	88	158
Loss | Commercial, Financial & Agricultural
Recorded investment in the loans and leases, by class and credit indicator
Loans and leases, gross	0	0
Loss | Leases
Recorded investment in the loans and leases, by class and credit indicator
Loans and leases, gross	0	0
Construction | Real Estate
Recorded investment in the loans and leases, by class and credit indicator
Loans and leases, gross	72,835	67,269
Net deferred costs	(408)	(342)
Total loans and leases, net of deferred costs	72,427	66,927
Construction | Pass | Real Estate
Recorded investment in the loans and leases, by class and credit indicator
Loans and leases, gross	72,835	67,269
Construction | Special Mention | Real Estate
Recorded investment in the loans and leases, by class and credit indicator
Loans and leases, gross	0	0
Construction | Substandard | Real Estate
Recorded investment in the loans and leases, by class and credit indicator
Loans and leases, gross	0	0
Construction | Loss | Real Estate
Recorded investment in the loans and leases, by class and credit indicator
Loans and leases, gross	0	0
Residential Mortgage | Real Estate
Recorded investment in the loans and leases, by class and credit indicator
Loans and leases, gross	1,513,104	1,424,384
Net deferred costs	3,832	3,821
Total loans and leases, net of deferred costs	1,516,936	1,428,205
Residential Mortgage | Pass | Real Estate
Recorded investment in the loans and leases, by class and credit indicator
Loans and leases, gross	1,512,276	1,422,240
Residential Mortgage | Special Mention | Real Estate
Recorded investment in the loans and leases, by class and credit indicator
Loans and leases, gross	0	0
Residential Mortgage | Substandard | Real Estate
Recorded investment in the loans and leases, by class and credit indicator
Loans and leases, gross	828	2,144
Residential Mortgage | Loss | Real Estate
Recorded investment in the loans and leases, by class and credit indicator
Loans and leases, gross	0	0
Home Equity | Real Estate
Recorded investment in the loans and leases, by class and credit indicator
Loans and leases, gross	472,918	468,966
Net deferred costs	233	0
Total loans and leases, net of deferred costs	473,151	468,966
Home Equity | Pass | Real Estate
Recorded investment in the loans and leases, by class and credit indicator
Loans and leases, gross	472,674	468,394
Home Equity | Special Mention | Real Estate
Recorded investment in the loans and leases, by class and credit indicator
Loans and leases, gross	0	0
Home Equity | Substandard | Real Estate
Recorded investment in the loans and leases, by class and credit indicator
Loans and leases, gross	244	572
Home Equity | Loss | Real Estate
Recorded investment in the loans and leases, by class and credit indicator
Loans and leases, gross	0	0
Commercial Mortgage | Real Estate
Recorded investment in the loans and leases, by class and credit indicator
Loans and leases, gross	1,094,256	1,041,685
Net deferred costs	(1,398)	(1,407)
Total loans and leases, net of deferred costs	1,092,858	1,040,278
Commercial Mortgage | Pass | Real Estate
Recorded investment in the loans and leases, by class and credit indicator
Loans and leases, gross	1,054,254	1,029,581
Commercial Mortgage | Special Mention | Real Estate
Recorded investment in the loans and leases, by class and credit indicator
Loans and leases, gross	26,711	10,412
Commercial Mortgage | Substandard | Real Estate
Recorded investment in the loans and leases, by class and credit indicator
Loans and leases, gross	13,291	1,692
Commercial Mortgage | Loss | Real Estate
Recorded investment in the loans and leases, by class and credit indicator
Loans and leases, gross	0	0
Consumer | Consumer
Recorded investment in the loans and leases, by class and credit indicator
Loans and leases, gross	501,273	492,268
Net deferred costs	(67)	(62)
Total loans and leases, net of deferred costs	501,206	492,206
Consumer | Pass | Consumer
Recorded investment in the loans and leases, by class and credit indicator
Loans and leases, gross	501,007	492,030
Consumer | Special Mention | Consumer
Recorded investment in the loans and leases, by class and credit indicator
Loans and leases, gross	0	0
Consumer | Substandard | Consumer
Recorded investment in the loans and leases, by class and credit indicator
Loans and leases, gross	178	80
Consumer | Loss | Consumer
Recorded investment in the loans and leases, by class and credit indicator
Loans and leases, gross	$ 88	$ 158