Consolidated Condensed Statements Of Changes In Stockholders' Equity - USD ($) $ in Thousands	Total	Preferred Stock [Member]	Preferred Stock [Member] Cumulative Effect, Period of Adoption, Adjusted Balance	Common Stock [Member]	Common Stock [Member] Cumulative Effect, Period of Adoption, Adjusted Balance	Retained Earnings [Member]	Retained Earnings [Member] Cumulative Effect, Period of Adoption, Adjusted Balance	Accumulated Other Comprehensive Income (loss) [Member]	Accumulated Other Comprehensive Income (loss) [Member] Cumulative Effect, Period of Adoption, Adjusted Balance	Treasury Stock, Common	Treasury Stock, Common Cumulative Effect, Period of Adoption, Adjusted Balance	Retained Earnings [Member] Cumulative Effect, Period of Adoption, Adjustment
Balance at Dec. 31, 2021		$ 0		$ 461,800		$ 776,294		$ 15,155		$ (142,490)
Net Income						38,875
Other comprehensive income (loss)								(55,624)
Dividends on common shares						(17,172)
Cash payment for fractional shares in dividend reinvestment plan				(2)
Stock Issued During Period, Value, Restricted Stock Award, Net of Forfeitures				4,508		964				3,021
Share-based Payment Arrangement, Expense				1,981
Balance at Mar. 31, 2022		0		459,271		797,033		(40,469)		(139,469)
Common Stock, Dividends, Per Share, Cash Paid	$ 1.04
Stock Issued During Period, Shares, Restricted Stock Award, Gross	29,757
Stock issued during period, shares, withheld for tax, tax restricted stock	18,658
Balance at Dec. 31, 2021		0		461,800		776,294		15,155		(142,490)
Net Income	$ 115,267
Other comprehensive income (loss)	(140,498)
Share-based Payment Arrangement, Expense	$ 4,800
Balance at Sep. 30, 2022		0		461,321		839,207		(125,343)		(139,013)
Stock issued during period, shares, withheld for tax, tax restricted stock	21,217
Balance at Mar. 31, 2022		0		459,271		797,033		(40,469)		(139,469)
Net Income						34,324
Other comprehensive income (loss)								(44,935)
Dividends on common shares						(17,116)
Share-based Payment Arrangement, Expense				1,374
Balance at Jun. 30, 2022		0		460,645		814,241		(85,404)		(139,469)
Common Stock, Dividends, Per Share, Cash Paid	$ 1.04
Net Income	$ 42,068					42,068
Other comprehensive income (loss)	(39,939)							(39,939)
Dividends on common shares						(17,101)
Stock Issued During Period, Value, Restricted Stock Award, Net of Forfeitures				765		1				456
Share-based Payment Arrangement, Expense	$ 1,400			1,441
Balance at Sep. 30, 2022		0		461,321		839,207		(125,343)		(139,013)
Common Stock, Dividends, Per Share, Cash Paid	$ 1.04
Stock Issued During Period, Shares, Restricted Stock Award, Gross	4,490
Stock issued during period, shares, withheld for tax, tax restricted stock	2,559
Balance at Dec. 31, 2022	$ 1,069,226	0	$ 0	462,404	$ 462,404	847,235	$ 846,932	(102,394)	$ (102,394)	(138,019)	$ (138,019)	$ (303)
Net Income						33,733
Other comprehensive income (loss)								12,361
Dividends on common shares						(17,285)
Stock Issued During Period, Value, Restricted Stock Award, Net of Forfeitures				5,309		862				3,564
Share-based Payment Arrangement, Expense				2,336
Balance at Mar. 31, 2023		0		459,431		862,518		(90,033)		(149,763)
Common Stock, Dividends, Per Share, Cash Paid	$ 1.05
Stock Issued During Period, Shares, Restricted Stock Award, Gross	34,484
Stock issued during period, shares, withheld for tax, tax restricted stock	21,981
Stock Repurchased During Period, Shares	124,000
Stock Repurchased During Period, Value	$ (15,308)
Balance at Dec. 31, 2022	1,069,226	0	$ 0	462,404	$ 462,404	847,235	$ 846,932	(102,394)	$ (102,394)	(138,019)	$ (138,019)	$ (303)
Net Income	102,234
Other comprehensive income (loss)	(13,496)
Share-based Payment Arrangement, Expense	5,400
Balance at Sep. 30, 2023	$ 1,085,564	0		461,849		896,627		(115,890)		(157,022)
Stock issued during period, shares, withheld for tax, tax restricted stock	23,973
Balance at Mar. 31, 2023		0		459,431		862,518		(90,033)		(149,763)
Net Income						31,584
Other comprehensive income (loss)								(6,753)
Dividends on common shares						(17,187)
Stock Issued During Period, Value, Restricted Stock Award, Net of Forfeitures				602		85				450
Share-based Payment Arrangement, Expense				1,749
Balance at Jun. 30, 2023		0		460,578		876,830		(96,786)		(151,865)
Common Stock, Dividends, Per Share, Cash Paid	$ 1.05
Stock Issued During Period, Shares, Restricted Stock Award, Gross	4,358
Stock issued during period, shares, withheld for tax, tax restricted stock	1,992
Stock Repurchased During Period, Shares	25,000
Stock Repurchased During Period, Value	$ (2,552)
Net Income	36,917					36,917
Other comprehensive income (loss)	(19,104)							(19,104)
Dividends on common shares						(17,120)
Share-based Payment Arrangement, Expense	1,300			1,271
Balance at Sep. 30, 2023	$ 1,085,564	$ 0		$ 461,849		$ 896,627		$ (115,890)		$ (157,022)
Common Stock, Dividends, Per Share, Cash Paid	$ 1.05
Stock issued during period, shares, withheld for tax, tax restricted stock	0
Stock Repurchased During Period, Shares	50,000
Stock Repurchased During Period, Value	$ (5,157)