Parent Company Cash Flow Statement (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Condensed Financial Statements, Captions [Line Items]
Net income		$ 205,122	$ 192,081	$ 239,502
Adjustments to reconcile net income to net cash provided by operating activities
Deferred income tax (benefit) expense		(3,283)	(10,600)	2,738
Change in other liabilities		(70,118)	5,543	(20,614)
Net cash provided by operating activities		251,160	229,921	276,994
Cash flows provided by (used in) investing activities
Net cash used in investing activities		5,050	(33,010)	(211,650)
Cash flows provided by (used in) financing activities
Proceeds from Lines of Credit		49,937	0	0
Proceeds from Issuance of Subordinated Long-term Debt		295,843	0	0
Repayments of Subordinated Debt		(60,000)	(50,000)	0
Issuance Of Restricted Stock Awards, Net of Issuance Cost		1,459	815	1,142
Cash received from stock option exercises		0	80	80
Proceeds from shares issued under direct stock purchase plan		2,549	3,254	2,662
Payments for Repurchase of Common Stock		(60,849)	(30,986)	(188,910)
Common dividends paid		(103,903)	(96,200)	(98,006)
Net cash provided by (used in) financing activities		295,802	(201,351)	(193,947)
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect		552,012	(4,440)	(128,603)
Parent Company [Member]
Condensed Financial Statements, Captions [Line Items]
Investments in subsidiaries	[1]	3,877,550	2,967,786
Net income		205,122	192,081	239,502
Adjustments to reconcile net income to net cash provided by operating activities
Amortization		684	22	98
Deferred income tax (benefit) expense		(1)	(1)	24
Change in prepaid income taxes and other assets		(5,843)	179	2,107
Change in other liabilities		3,975	(2,560)	52
Equity in undistributed income of subsidiaries		65,743	13,745	17,656
Net cash provided by operating activities		138,194	175,976	224,127
Cash flows provided by (used in) investing activities
Payments to subsidiaries		(225,000)	0	0
Payments for (Proceeds from) Businesses and Interest in Affiliates		21,100	0	0
Net cash used in investing activities		(246,100)	0	0
Cash flows provided by (used in) financing activities
Proceeds from Lines of Credit		49,937	0	0
Proceeds from Issuance of Subordinated Long-term Debt		295,843	0	0
Issuance Of Restricted Stock Awards, Net of Issuance Cost		(1,459)	(815)	(1,142)
Cash received from stock option exercises		0	80	80
Proceeds from shares issued under direct stock purchase plan		2,549	3,254	2,662
Payments for Repurchase of Common Stock		(60,849)	(30,986)	(188,910)
Common dividends paid		(103,903)	(96,200)	(98,006)
Net cash provided by (used in) financing activities		122,118	(174,667)	(285,316)
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect		14,212	1,309	(61,189)
Cash	[2]	124,309	110,097
Cash and cash equivalents at beginning of year		110,097	108,788	169,977
Cash and cash equivalents at end of period		124,309	110,097	108,788
Subordinated Debt [Member] | Parent Company [Member]
Cash flows provided by (used in) financing activities
Repayments of Subordinated Debt		$ 60,000	$ (50,000)	$ 0

[1] Majority of balance eliminated in consolidation

[2] Entire balance eliminated in consolidation.