CONDENSED FINANCIAL INFORMATION (parent company only) - Statements of Cash Flows (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Cash Flow From Operating Activities:
Net income	$ 223,786	$ 222,089	$ 205,531
Adjustments to reconcile net income to net cash provided by operating activities
Share-based compensation	5,158	4,652	4,762
Net cash provided by operating activities	258,833	284,289	215,341
Cash Flow From Investing Activities:
Cash paid in acquisition	0	(79,324)	(3,225)
Net cash used in investing activities	(344,425)	(462,685)	(1,477,405)
Cash Flows from Financing Activities:
Cash dividends on common stock	(80,061)	(72,748)	(61,230)
Cash dividends on preferred stock	(1,875)	(1,406)	0
Stock issued under employee benefit plans	754	706	605
Stock issued under dividend reinvestment and stock purchase plan	2,180	2,056	1,880
Stock options exercised	1,110	358	198
Repurchase of common stock	0	0	(25,444)
Net cash provided by financing activities	75,647	133,844	1,236,314
Net Change in Cash and Cash Equivalents	(9,945)	(44,552)	(25,750)
Cash and Cash Equivalents, January 1	122,594	167,146	192,896
Cash and Cash Equivalents, December 31	112,649	122,594	167,146
Parent
Cash Flow From Operating Activities:
Net income	223,786	222,089	205,531
Adjustments to reconcile net income to net cash provided by operating activities
Share-based compensation	1,803	1,659	1,563
Distributions in excess of (equity in undistributed) income of subsidiaries	(105,984)	(145,057)	(55,162)
Other adjustments	(2,446)	(5,925)	(288)
Net cash provided by operating activities	117,159	72,766	151,644
Cash Flow From Investing Activities:
Cash paid in acquisition	0	(72,494)	0
Proceeds from business divestitures	4,852	0	0
Net cash used in investing activities	4,852	(72,494)	0
Cash Flows from Financing Activities:
Cash dividends on common stock	(80,061)	(72,748)	(61,230)
Cash dividends on preferred stock	(1,875)	(1,406)	0
Stock issued under employee benefit plans	754	706	605
Stock issued under dividend reinvestment and stock purchase plan	2,180	2,056	1,880
Stock options exercised	1,110	358	198
Repurchase of common stock	0	0	(25,444)
Net cash provided by financing activities	(77,892)	(71,034)	(83,991)
Net Change in Cash and Cash Equivalents	44,119	(70,762)	67,653
Cash and Cash Equivalents, January 1	56,739	127,501	59,848
Cash and Cash Equivalents, December 31	$ 100,858	$ 56,739	$ 127,501