Condensed Consolidated Statement of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Preferred Stock	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)
Beginning balance at Dec. 31, 2020	$ 692,216	$ 0	$ 0	$ 362,945	$ 301,419	$ 27,852
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	65,666				65,666
Other comprehensive (loss) income, net of tax	(20,207)					(20,207)
Amortization of unearned compensation	1,233			1,233
Exercise of stock options	769			769
Stock option expense	55			55
Repurchase of outstanding stock	7,607			7,607
Net settlement of share awards	(1,347)			(1,347)
Stock retirement plans	(4,094)			(4,094)
Cash dividends on common stock	(18,142)				(18,142)
Ending balance at Sep. 30, 2021	708,542	0	0	351,954	348,943	7,645
Beginning balance at Jun. 30, 2021	710,374	0	0	359,227	332,509	18,638
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	23,071				23,071
Other comprehensive (loss) income, net of tax	(10,993)					(10,993)
Amortization of unearned compensation	449			449
Stock option expense	13			13
Repurchase of outstanding stock	7,607			7,607
Stock retirement plans	(128)			(128)
Cash dividends on common stock	(6,637)				(6,637)
Ending balance at Sep. 30, 2021	708,542	0	0	351,954	348,943	7,645
Beginning balance at Dec. 31, 2021	723,209	0	0	352,122	363,742	7,345
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	72,243				72,243
Other comprehensive (loss) income, net of tax	(130,466)					(130,466)
Amortization of unearned compensation	1,770			1,770
Exercise of stock options	108			108
Stock option expense	13			13
Net settlement of share awards	(1,785)			(1,785)
Stock retirement plans	609			609
Cash dividends on common stock	(20,708)				(20,708)
Ending balance at Sep. 30, 2022	644,993	0	0	352,837	415,277	(123,121)
Beginning balance at Jun. 30, 2022	657,865	0	0	352,412	398,517	(93,064)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	23,821				23,821
Other comprehensive (loss) income, net of tax	(30,057)					(30,057)
Amortization of unearned compensation	627			627
Exercise of stock options	14			14
Net settlement of share awards	(89)			(89)
Stock retirement plans	(127)			(127)
Cash dividends on common stock	(7,061)				(7,061)
Ending balance at Sep. 30, 2022	$ 644,993	$ 0	$ 0	$ 352,837	$ 415,277	$ (123,121)