LOANS - Impaired Loans Summary (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Impaired loans summary
Nonaccrual loans	$ 60,211	$ 47,892
Accruing loans past due 90 days or more	4,825	375
Restructured loans - nonaccrual	1,910	9,446
Restructured loans - accruing	3,009	13,093
Total nonperforming loans	69,955	70,806
Originated
Impaired loans summary
Nonaccrual loans	56,956	43,797
Accruing loans past due 90 days or more	2,903	375
Restructured loans - nonaccrual	899	8,063
Restructured loans - accruing	7	4,255
Total nonperforming loans	60,765	56,490
Acquired
Impaired loans summary
Nonaccrual loans	3,255	4,095
Accruing loans past due 90 days or more	1,922	0
Restructured loans - nonaccrual	1,011	1,383
Restructured loans - accruing	3,002	8,838
Total nonperforming loans	$ 9,190	$ 14,316