Parent Company Statement of Cash Flows (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Net Income (Loss) Attributable to Parent	$ 148,351	$ 153,945	$ 127,923
Share-based Payment Arrangement, Noncash Expense	7,199	8,021	7,272
Debt and Equity Securities, Unrealized Gain (Loss)	207	(1,218)	245
Increase (Decrease) in Other Operating Assets	4,467	(12,406)	(9,321)
Increase (Decrease) in Other Operating Liabilities	(4,814)	(7,939)	(6,302)
Net cash provided by operating activities	134,862	157,332	111,646
Other investing activities, net	(9,021)	2,332	(2,621)
Net cash used in investing activities	(403,699)	(412,141)	(455,902)
Repayments of Long-term Debt	0	32,500	170,529
Payments Related to Tax Withholding for Share-based Compensation	2,761	2,403	1,002
Net cash (used in) provided by financing activities	239,385	103,515	554,774
Proceeds from Sale of Debt Securities	0	934	312,160
Treasury Stock, Common [Member]
Payments for Repurchase of Equity	0	16,048	7,507
Parent Company
Net Income (Loss) Attributable to Parent	148,351	153,945	127,923
Undistributed Losses Of Subsidiaries	38,818	49,876	41,730
Compensation expense for issuance of treasury shares to directors	1,320	1,676	1,274
Share-based Payment Arrangement, Noncash Expense	5,879	6,345	5,998
Increase (Decrease) in Other Operating Assets	2,514	(8,249)	(6,632)
Increase (Decrease) in Other Operating Liabilities	4,896	(2,407)	(6,325)
Net cash provided by operating activities	119,321	116,714	94,017
Net cash used in investing activities	(9,021)	3,266	(2,621)
Payments of Dividends	76,604	74,306	70,353
Proceeds from Issuance of Long-term Debt	0	0	172,620
Repayments of Long-term Debt	0	(32,500)	(10,000)
Cash Payment For Fractional Shares	2	6	3
Payments Related to Tax Withholding for Share-based Compensation	(2,761)	(2,403)	(1,002)
Net cash (used in) provided by financing activities	(79,367)	(125,263)	83,755
Increase (decrease) in cash and cash equivalents	30,933	(5,283)	175,151
Cash	274,464	243,531	248,814	$ 73,663
Proceeds from Sale of Debt Securities	$ 0	$ 934	$ 0