LOANS - Impaired Loans (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018 USD ($) loan	Sep. 30, 2017 USD ($)	Sep. 30, 2018 USD ($) loan	Sep. 30, 2017 USD ($)	Dec. 31, 2017 USD ($)
Impaired loans
Charge-off of one loan and sales and payoffs | loan			1
Recorded Investment
With no related allowance recorded	$ 15,550		$ 15,550		$ 20,784
With an allowance recorded	0		0		1,708
Total impaired loans	15,550		15,550		22,492
Unpaid Principal Balance
With no related allowance recorded	15,557		15,557		21,683
With an allowance recorded	0		0		3,235
Total impaired loans	15,557		15,557		24,918
Related Allocated Allowance
With an allowance recorded	0		0		1,708
Total impaired loans	0		0		1,708
Average Recorded Investment
With no related allowance recorded	15,260	$ 12,278	14,731	$ 8,178
With an allowance recorded	0	4,510	0	1,638
Average recorded investment in impaired loans	15,260	16,788	14,731	9,816
Interest Income Recognized
With no related allowance recorded	109	109	307	376
With an allowance recorded	0	111	0	112
Total impaired loans	109	220	307	488
Commercial Real Estate | Mortgage loans | Owner occupied
Recorded Investment
With no related allowance recorded	277		277		2,073
With an allowance recorded	0		0		0
Total impaired loans	277		277		2,073
Unpaid Principal Balance
With no related allowance recorded	284		284		2,073
With an allowance recorded	0		0		0
Total impaired loans	284		284		2,073
Related Allocated Allowance
With an allowance recorded	0		0		0
Total impaired loans	0		0		0
Average Recorded Investment
With no related allowance recorded	268	0	151	0
With an allowance recorded	0	0	0	0
Average recorded investment in impaired loans	268	0	151	0
Interest Income Recognized
With no related allowance recorded	0	0	0	0
With an allowance recorded	0	0	0	0
Total impaired loans	0	0	0	0
Commercial Real Estate | Mortgage loans | Non-owner occupied
Recorded Investment
With no related allowance recorded	2,063		2,063		9,089
With an allowance recorded	0		0		0
Total impaired loans	2,063		2,063		9,089
Unpaid Principal Balance
With no related allowance recorded	2,063		2,063		9,089
With an allowance recorded	0		0		0
Total impaired loans	2,063		2,063		9,089
Related Allocated Allowance
With an allowance recorded	0		0		0
Total impaired loans	0		0		0
Average Recorded Investment
With no related allowance recorded	1,763	8,906	1,366	6,352
With an allowance recorded	0	0	0	0
Average recorded investment in impaired loans	1,763	8,906	1,366	6,352
Interest Income Recognized
With no related allowance recorded	10	100	18	298
With an allowance recorded	0	0	0	0
Total impaired loans	10	100	18	298
Residential real estate | Mortgage loans | Residential Real Estate Mortgage Loans
Recorded Investment
With no related allowance recorded	0		0		0
With an allowance recorded	0		0		0
Total impaired loans	0		0		0
Unpaid Principal Balance
With no related allowance recorded	0		0		0
With an allowance recorded	0		0		0
Total impaired loans	0		0		0
Related Allocated Allowance
With an allowance recorded	0		0		0
Total impaired loans	0		0		0
Average Recorded Investment
With no related allowance recorded	0	0	0	0
With an allowance recorded	0	0	0	0
Average recorded investment in impaired loans	0	0	0	0
Interest Income Recognized
With no related allowance recorded	0	0	0	0
With an allowance recorded	0	0	0	0
Total impaired loans	0	0	0	0
Residential real estate | Mortgage loans | Home equity
Recorded Investment
With no related allowance recorded	0		0		100
With an allowance recorded	0		0		0
Total impaired loans	0		0		100
Unpaid Principal Balance
With no related allowance recorded	0		0		100
With an allowance recorded	0		0		0
Total impaired loans	0		0		100
Related Allocated Allowance
With an allowance recorded	0		0		0
Total impaired loans	0		0		0
Average Recorded Investment
With no related allowance recorded	0	0	0	0
With an allowance recorded	0	0	0	0
Average recorded investment in impaired loans	0	0	0	0
Interest Income Recognized
With no related allowance recorded	0	0	0	0
With an allowance recorded	0	0	0	0
Total impaired loans	0	0	0	0
Commercial and industrial | Secured
Recorded Investment
With no related allowance recorded	8,076		8,076		7,368
With an allowance recorded	0		0		0
Total impaired loans	8,076		8,076		7,368
Unpaid Principal Balance
With no related allowance recorded	8,076		8,076		8,013
With an allowance recorded	0		0		0
Total impaired loans	8,076		8,076		8,013
Related Allocated Allowance
With an allowance recorded	0		0		0
Total impaired loans	0		0		0
Average Recorded Investment
With no related allowance recorded	8,086	3,030	8,130	1,459
With an allowance recorded	0	1,216	0	540
Average recorded investment in impaired loans	8,086	4,246	8,130	1,999
Interest Income Recognized
With no related allowance recorded	57	5	171	66
With an allowance recorded	0	6	0	6
Total impaired loans	57	11	171	72
Commercial and industrial | Unsecured
Recorded Investment
With no related allowance recorded	5,134		5,134		2,154
With an allowance recorded	0		0		1,708
Total impaired loans	5,134		5,134		3,862
Unpaid Principal Balance
With no related allowance recorded	5,134		5,134		2,408
With an allowance recorded	0		0		3,235
Total impaired loans	5,134		5,134		5,643
Related Allocated Allowance
With an allowance recorded	0		0		1,708
Total impaired loans	0		0		1,708
Average Recorded Investment
With no related allowance recorded	5,143	342	5,084	367
With an allowance recorded	0	3,294	0	1,098
Average recorded investment in impaired loans	5,143	3,636	5,084	1,465
Interest Income Recognized
With no related allowance recorded	42	4	118	12
With an allowance recorded	0	105	0	106
Total impaired loans	42	$ 109	118	$ 118
Other real estate owned
Recorded Investment
Total impaired loans	$ 200		$ 200		$ 0
Interest Income Recognized
Number of impaired financing receivables | loan	1		1