Condensed Financial Information (parent company only) - Statements of Cash Flows (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Cash Flow From Operating Activities:
Net income	$ 222,089	$ 205,531	$ 148,600
Adjustments to reconcile net income to net cash provided by operating activities
Share-based compensation	4,652	4,762	4,600
Net cash provided by operating activities	268,045	207,382	203,831
Cash Flow From Investing Activities:
Cash paid in acquisition	(79,324)	(3,225)	0
Net cash used in investing activities	(446,441)	(1,469,446)	(1,552,025)
Cash Flows from Financing Activities:
Cash dividends on common stock	(72,748)	(61,230)	(56,542)
Cash dividends on preferred stock	(1,406)	0	0
Repayment of borrowings	(1,332,889)	(96,204)	(621,548)
Stock issued under employee benefit plans	706	605	639
Stock issued under dividend reinvestment and stock purchase plan	2,056	1,880	1,726
Stock options exercised	358	198	115
Repurchase of common stock	0	(25,444)	(55,912)
Net cash provided by financing activities	133,844	1,236,314	1,363,889
Net Change in Cash and Cash Equivalents	(44,552)	(25,750)	15,695
Cash and Cash Equivalents, January 1	167,146	192,896	177,201
Cash and Cash Equivalents, December 31	122,594	167,146	192,896
Parent
Cash Flow From Operating Activities:
Net income	222,089	205,531	148,600
Adjustments to reconcile net income to net cash provided by operating activities
Share-based compensation	1,659	1,563	1,502
Distributions in excess of (equity in undistributed) income of subsidiaries	(145,057)	(55,162)	(89,465)
Other adjustments	(6,258)	(1,173)	1,537
Investment in subsidiaries - operating activities	333	885	235
Net cash provided by operating activities	72,766	151,644	62,409
Cash Flow From Investing Activities:
Cash paid in acquisition	(72,494)	0	0
Net cash used in investing activities	(72,494)	0	0
Cash Flows from Financing Activities:
Cash dividends on common stock	(72,748)	(61,230)	(56,542)
Cash dividends on preferred stock	(1,406)	0	0
Repayment of borrowings	0	0	(20,310)
Stock issued under employee benefit plans	706	605	639
Stock issued under dividend reinvestment and stock purchase plan	2,056	1,880	1,726
Stock options exercised	358	198	115
Repurchase of common stock	0	(25,444)	(55,912)
Net cash provided by financing activities	(71,034)	(83,991)	(130,284)
Net Change in Cash and Cash Equivalents	(70,762)	67,653	(67,875)
Cash and Cash Equivalents, January 1	127,501	59,848	127,723
Cash and Cash Equivalents, December 31	$ 56,739	$ 127,501	$ 59,848