DEPOSITS (Summary of Certain Deposits) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Non-interest bearing demand deposits	$ 946,838	$ 885,622
Savings and transaction accounts:
Savings deposits	247,903	263,570
Interest bearing demand deposits	3,097,227	3,123,033
Time deposits:
Other time deposits	273,533	251,218
Deposits of $100,000 to $250,000	268,058	236,354
Deposits of $250,000 or more	878,163	925,011
Total deposits	4,044,065	4,008,655
Demand Deposits [Member]
Savings and transaction accounts:
Interest bearing demand deposits	$ 1,429,570	$ 1,446,880