Consolidated Statements of Changes in Shareholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Stock [Member]	Capital Surplus [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Balance at Dec. 31, 2021	$ 1,741,311	$ 12,845	$ 175,913	$ 1,585,113	$ (32,560)
Balance (in shares) at Dec. 31, 2021		61,648,679
Net income per consolidated statements of income	29,211			29,211
Other comprehensive income (loss), net of tax	(116,096)				(116,096)
Common stock dividends paid ($0.23 per share)	(14,186)			(14,186)
Shares withheld to pay taxes, long-term incentive plan	(1,009)	$ 19	(1,028)
Shares withheld to pay taxes, long-term incentive plan (in shares)		93,944
Repurchase and retirement of common stock	(9,094)	$ (58)	(9,036)
Repurchase and retirement of common stock (in shares)		(279,231)
Compensation expense, long-term incentive plan	1,245		1,245
Balance at Mar. 31, 2022	1,631,382	$ 12,806	167,094	1,600,138	(148,656)
Balance (in shares) at Mar. 31, 2022		61,463,392
Balance at Dec. 31, 2021	1,741,311	$ 12,845	175,913	1,585,113	(32,560)
Balance (in shares) at Dec. 31, 2021		61,648,679
Net income per consolidated statements of income	63,495
Other comprehensive income (loss), net of tax	(174,582)
Balance at Jun. 30, 2022	1,586,696	$ 12,752	160,876	1,620,210	(207,142)
Balance (in shares) at Jun. 30, 2022		61,201,123
Balance at Mar. 31, 2022	1,631,382	$ 12,806	167,094	1,600,138	(148,656)
Balance (in shares) at Mar. 31, 2022		61,463,392
Net income per consolidated statements of income	34,284			34,284
Other comprehensive income (loss), net of tax	(58,486)				(58,486)
Common stock dividends paid ($0.23 per share)	(14,212)			(14,212)
Shares withheld to pay taxes, long-term incentive plan	(7)		(7)
Shares withheld to pay taxes, long-term incentive plan (in shares)		513
Repurchase and retirement of common stock	(7,505)	$ (54)	(7,451)
Repurchase and retirement of common stock (in shares)		(262,782)
Compensation expense, long-term incentive plan	1,240		1,240
Balance at Jun. 30, 2022	1,586,696	$ 12,752	160,876	1,620,210	(207,142)
Balance (in shares) at Jun. 30, 2022		61,201,123
Balance at Dec. 31, 2022	$ 1,492,268	$ 12,705	154,645	1,600,321	(275,403)
Balance (in shares) at Dec. 31, 2022	60,977,686	60,977,686
Net income per consolidated statements of income	$ 50,300			50,300
Other comprehensive income (loss), net of tax	33,022				33,022
Common stock dividends paid ($0.23 per share)	(14,158)			(14,158)
Shares withheld to pay taxes, long-term incentive plan	(1,048)	$ 15	(1,063)
Shares withheld to pay taxes, long-term incentive plan (in shares)		70,830
Compensation expense, long-term incentive plan	1,715		1,715
Balance at Mar. 31, 2023	1,562,099	$ 12,720	155,297	1,636,463	(242,381)
Balance (in shares) at Mar. 31, 2023		61,048,516
Balance at Dec. 31, 2022	$ 1,492,268	$ 12,705	154,645	1,600,321	(275,403)
Balance (in shares) at Dec. 31, 2022	60,977,686	60,977,686
Net income per consolidated statements of income	$ 95,337
Other comprehensive income (loss), net of tax	9,699
Balance at Jun. 30, 2023	$ 1,571,193	$ 12,724	156,834	1,667,339	(265,704)
Balance (in shares) at Jun. 30, 2023	61,069,036	61,069,036
Balance at Mar. 31, 2023	$ 1,562,099	$ 12,720	155,297	1,636,463	(242,381)
Balance (in shares) at Mar. 31, 2023		61,048,516
Net income per consolidated statements of income	45,037			45,037
Other comprehensive income (loss), net of tax	(23,323)				(23,323)
Common stock dividends paid ($0.23 per share)	(14,161)			(14,161)
Shares withheld to pay taxes, long-term incentive plan	(22)	$ 4	(26)
Shares withheld to pay taxes, long-term incentive plan (in shares)		20,520
Compensation expense, long-term incentive plan	1,563		1,563
Balance at Jun. 30, 2023	$ 1,571,193	$ 12,724	$ 156,834	$ 1,667,339	$ (265,704)
Balance (in shares) at Jun. 30, 2023	61,069,036	61,069,036