SECURITIES (Schedule of Carrying Value, Gross Unrealized Gains and Losses and Estimated Fair Value of Securities) (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Schedule of Held-to-maturity Securities [Line Items]
Total HTM securities	$ 556,579	$ 492,272
Gross Unrealized Gains	51,137
Gross Unrealized (Losses)	0
Estimated Fair Value	607,716	499,501
Obligations of states and political subdivisions
Schedule of Held-to-maturity Securities [Line Items]
Total HTM securities	546,515	492,272
Gross Unrealized Gains	51,002	7,375
Gross Unrealized (Losses)	0	(146)
Estimated Fair Value	597,517	$ 499,501
Mortgage-backed securities
Schedule of Held-to-maturity Securities [Line Items]
Total HTM securities	10,064
Gross Unrealized Gains	135
Gross Unrealized (Losses)	0
Estimated Fair Value	$ 10,199