INCOME TAXES (Effective Income Tax Rate Reconciliation) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Computed "expected" tax on net income									$ 56,228	$ 57,804	$ 36,538
Increase (decrease) resulting from:
Nontaxable interest income									(5,804)	(5,504)	(4,011)
State income taxes, net of federal tax benefit									10,523	11,026	7,930
Tax credits									(6,613)	(7,613)	(4,521)
Valuation allowance									13	(440)	(374)
Excess tax expense/(benefit) on stock compensation									(113)	(270)	80
Other									1,339	332	411
Total income tax expense	$ 13,936	$ 14,118	$ 15,402	$ 12,117	$ 10,271	$ 13,250	$ 16,481	$ 15,333	$ 55,573	$ 55,335	$ 36,053
Effective tax rates									20.80%	20.10%	20.70%