LOANS AND LEASES - Investment in Impaired Loans (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Financing Receivable, Impaired [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	$ 42,368		$ 42,368		$ 24,082
Current balance	62,681		62,681		41,627
Contractual Principal Balance	77,057		77,057		47,857
Related Allowance	1,790		1,790		779
Average current balance	62,493	$ 53,260	52,960	$ 54,402
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	39	15	67	67
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	317	293	828	941
Interest income recognized	356	308	895	1,008
Commercial
Financing Receivable, Impaired [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	4,310		4,310		5,229
Current balance	11,985		11,985		7,331
Contractual Principal Balance	15,810		15,810		8,629
Related Allowance	1,562		1,562		169
Average current balance	11,611	15,562	9,841	16,132
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	28	2	34	26
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	63	63	162	259
Interest income recognized	91	65	196	285
Lease financing
Financing Receivable, Impaired [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	0		0		82
Current balance	0		0		82
Contractual Principal Balance	0		0		82
Related Allowance	0		0		0
Average current balance	0	91	21	120
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	0	0	0	0
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	0	1	0	3
Interest income recognized	0	1	0	3
Construction real estate
Financing Receivable, Impaired [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	10		10		29
Current balance	10		10		29
Contractual Principal Balance	27		27		60
Related Allowance	0		0		0
Average current balance	17	950	22	744
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	0	0	0	0
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	0	0	2	0
Interest income recognized	0	0	2	0
Commercial real estate
Financing Receivable, Impaired [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	20,338		20,338		10,616
Current balance	28,390		28,390		21,542
Contractual Principal Balance	35,028		35,028		23,957
Related Allowance	66		66		448
Average current balance	29,701	23,839	26,420	24,076
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	3	5	9	18
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	136	147	375	451
Interest income recognized	139	152	384	469
Residential real estate
Financing Receivable, Impaired [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	11,365		11,365		4,140
Current balance	15,310		15,310		7,932
Contractual Principal Balance	18,116		18,116		9,208
Related Allowance	160		160		160
Average current balance	14,283	8,636	10,918	8,927
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	7	7	21	20
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	86	55	209	147
Interest income recognized	93	62	230	167
Home equity
Financing Receivable, Impaired [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	6,018		6,018		3,743
Current balance	6,654		6,654		4,456
Contractual Principal Balance	7,437		7,437		5,499
Related Allowance	2		2		2
Average current balance	6,563	3,892	5,439	4,052
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	1	1	3	3
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	31	26	78	77
Interest income recognized	32	27	81	80
Installment
Financing Receivable, Impaired [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	327		327		243
Current balance	332		332		255
Contractual Principal Balance	639		639		422
Related Allowance	0		0		0
Average current balance	318	290	299	351
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	0	0	0	0
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	1	1	2	4
Interest income recognized	1	1	2	4
Loans with no related allowance recorded [member]
Financing Receivable, Impaired [Line Items]
Current balance	57,104		57,104		37,183
Contractual Principal Balance	70,826		70,826		43,405
Related Allowance	0		0		0
Average current balance	58,767	49,608	49,550	49,199
Loans with no related allowance recorded [member] | Commercial
Financing Receivable, Impaired [Line Items]
Current balance	9,209		9,209		7,162
Contractual Principal Balance	13,034		13,034		8,460
Related Allowance	0		0		0
Average current balance	10,033	13,730	8,950	14,669
Loans with no related allowance recorded [member] | Lease financing
Financing Receivable, Impaired [Line Items]
Current balance	0		0		82
Contractual Principal Balance	0		0		82
Related Allowance	0		0		0
Average current balance	0	91	21	120
Loans with no related allowance recorded [member] | Construction real estate
Financing Receivable, Impaired [Line Items]
Current balance	10		10		29
Contractual Principal Balance	27		27		60
Related Allowance	0		0		0
Average current balance	17	950	22	744
Loans with no related allowance recorded [member] | Commercial real estate
Financing Receivable, Impaired [Line Items]
Current balance	26,722		26,722		18,423
Contractual Principal Balance	32,706		32,706		20,837
Related Allowance	0		0		0
Average current balance	28,689	23,187	25,044	21,563
Loans with no related allowance recorded [member] | Residential real estate
Financing Receivable, Impaired [Line Items]
Current balance	14,277		14,277		6,876
Contractual Principal Balance	17,083		17,083		8,145
Related Allowance	0		0		0
Average current balance	13,247	7,569	9,875	7,801
Loans with no related allowance recorded [member] | Home equity
Financing Receivable, Impaired [Line Items]
Current balance	6,554		6,554		4,356
Contractual Principal Balance	7,337		7,337		5,399
Related Allowance	0		0		0
Average current balance	6,463	3,791	5,339	3,951
Loans with no related allowance recorded [member] | Installment
Financing Receivable, Impaired [Line Items]
Current balance	332		332		255
Contractual Principal Balance	639		639		422
Related Allowance	0		0		0
Average current balance	318	290	299	351
Impaired Financing Receivables With Related Allowance [Member]
Financing Receivable, Impaired [Line Items]
Current balance	5,577		5,577
Contractual Principal Balance	6,231		6,231
Related Allowance	1,790		1,790
Impaired Financing Receivables With Related Allowance [Member] | Commercial
Financing Receivable, Impaired [Line Items]
Current balance	2,776		2,776		169
Contractual Principal Balance	2,776		2,776		169
Related Allowance	1,562		1,562		169
Average current balance	1,578	1,832	891	1,463
Impaired Financing Receivables With Related Allowance [Member] | Lease financing
Financing Receivable, Impaired [Line Items]
Current balance	0		0		0
Contractual Principal Balance	0		0		0
Related Allowance	0		0		0
Average current balance	0	0	0	0
Impaired Financing Receivables With Related Allowance [Member] | Construction real estate
Financing Receivable, Impaired [Line Items]
Current balance	0		0		0
Contractual Principal Balance	0		0		0
Related Allowance	0		0		0
Average current balance	0	0	0	0
Impaired Financing Receivables With Related Allowance [Member] | Commercial real estate
Financing Receivable, Impaired [Line Items]
Current balance	1,668		1,668		3,119
Contractual Principal Balance	2,322		2,322		3,120
Related Allowance	66		66		448
Average current balance	1,012	652	1,376	2,513
Impaired Financing Receivables With Related Allowance [Member] | Residential real estate
Financing Receivable, Impaired [Line Items]
Current balance	1,033		1,033		1,056
Contractual Principal Balance	1,033		1,033		1,063
Related Allowance	160		160		160
Average current balance	1,036	1,067	1,043	1,126
Impaired Financing Receivables With Related Allowance [Member] | Home equity
Financing Receivable, Impaired [Line Items]
Current balance	100		100		100
Contractual Principal Balance	100		100		100
Related Allowance	2		2		2
Average current balance	100	101	100	101
Impaired Financing Receivables With Related Allowance [Member] | Installment
Financing Receivable, Impaired [Line Items]
Current balance	0		0		0
Contractual Principal Balance	0		0		0
Related Allowance	0		0		0
Average current balance	0	0	0	0
Impaired Financing Receivables With Related Allowance [Member]
Financing Receivable, Impaired [Line Items]
Current balance					4,444
Contractual Principal Balance					4,452
Related Allowance					$ 779
Average current balance	$ 3,726	$ 3,652	$ 3,410	$ 5,203