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, 2019	Dec. 31, 2018	Dec. 31, 2017
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 12,156	$ 12,156
Accumulated Amortization	(4,315)	(2,368)
Net Carrying Amount	7,841	9,788
Goodwill	347,149	347,149	$ 85,768
Core deposits [Member]
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	10,678	10,678
Accumulated Amortization	(3,689)	1,941
Net Carrying Amount	$ 6,989	$ 8,737
Core deposits [Member] | Weighted average [Member]
Finite Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	8 years	9 years
Other Identifiable Intangible Assets
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 1,478	$ 1,478
Accumulated Amortization	(626)	(427)
Net Carrying Amount	$ 852	$ 1,051
Other Identifiable Intangible Assets | Weighted average [Member]
Finite Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	9 years 8 months 12 days	10 years 7 months 6 days