GOODWILL AND OTHER INTANGIBLE ASSETS (Gross Carrying Amouns and Accumulated Amortization of Intangible Assets and Goodwill) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 12,156	$ 786
Accumulated Amortization	(2,368)	(206)
Net Carrying Amount	9,788	580
Goodwill	347,149	85,768	$ 85,768
Core deposits [Member]
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	10,678	0
Accumulated Amortization	(1,941)	0
Net Carrying Amount	$ 8,737	0
Core deposits [Member] | Weighted average [Member]
Finite Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	9 years
Other Identifiable Intangible Assets
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 1,478	786
Accumulated Amortization	(427)	(206)
Net Carrying Amount	$ 1,051	$ 580
Other Identifiable Intangible Assets | Weighted average [Member]
Finite Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	10 years 7 months 6 days	13 years 1 month 6 days