INCOME TAXES (Computation of Differences Between Financial Statement Tax Expense And Amounts) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income taxes at statutory federal rate of 21% (2018) and 35% (prior years)									$ 20,778	$ 31,372	$ 27,026
Increase (decrease) in taxes resulting from:
Tax exempt income									(1,434)	(2,015)	(1,498)
Nondeductible expense									165	193	190
State income tax, net of federal tax effect									1,077	846	726
Captive insurance premium income									(292)	(378)	(361)
Tax credits									(412)	(326)	(311)
Bank owned life insurance									(303)	(619)	(554)
Long - term incentive plan									(641)	(854)	0
Revaluation deferred tax asset at 21% rate									(408)	4,137	0
Other									3	(52)	(85)
Total income tax expense	$ 5,480	$ 4,679	$ 5,110	$ 3,264	$ 11,779	$ 7,573	$ 7,394	$ 5,558	$ 18,533	$ 32,304	$ 25,133