GOODWILL AND IDENTIFIABLE INTANGIBLE ASSETS (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Goodwill	$ 256,105	$ 231,806	$ 221,526
Other Intangible Assets	15,250	9,341
Total goodwill and other intangible assets	271,355	241,147
Core Deposits [Member]
Finite-Lived Intangible Assets [Line Items]
Other Intangible Assets	13,692	8,636
Other identifiable Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Other Intangible Assets	$ 1,558	$ 705