Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Interest income:
Loans, including fees	$ 1,355,852	$ 1,452,402	$ 1,379,263
Loans held for sale	1,652	1,640	1,723
Securities-taxable	220,513	194,227	189,386
Securities-tax exempt	16,015	17,698	18,627
Short-term investments	20,588	27,024	31,498
Total interest income	1,614,620	1,692,991	1,620,497
Interest expense:
Deposits	470,348	574,441	443,924
Short-term borrowings	23,687	24,372	66,657
Long-term debt	11,813	12,257	12,317
Total interest expense	505,848	611,070	522,898
Net interest income	1,108,772	1,081,921	1,097,599
Provision for credit losses	51,183	52,167	59,103
Net interest income after provision for credit losses	1,057,589	1,029,754	1,038,496
Noninterest income:
Securities transactions, net	(11)	0	(65,380)
Other income	67,582	60,001	71,436
Total noninterest income	406,447	364,129	288,480
Noninterest expense:
Compensation expense	385,660	380,591	376,055
Employee benefits	89,731	88,786	84,740
Personnel expense	475,391	469,377	460,795
Net occupancy expense	55,871	53,650	51,573
Equipment expense	17,020	17,432	18,852
Data processing expense	127,227	121,880	117,694
Professional services expense	57,080	41,935	38,331
Amortization of intangibles	9,953	9,413	11,556
Deposit insurance and regulatory fees	17,992	24,209	49,979
Other real estate and foreclosed assets expense (income)	3,091	(2,469)	(624)
Other expense	88,016	84,483	88,692
Total noninterest expense	851,641	819,910	836,848
Income before income taxes	612,395	573,973	490,128
Income tax expense	126,322	113,158	97,526
Net income	$ 486,073	$ 460,815	$ 392,602
Earnings per common share - basic	$ 5.7	$ 5.3	$ 4.51
Earnings per common share - diluted	5.67	5.28	4.5
Dividends paid per share	$ 1.8	$ 1.5	$ 1.2
Weighted average shares outstanding - basic	84,905	86,346	86,130
Weighted average shares outstanding - diluted	85,440	86,648	86,423
Service charges on deposit accounts
Noninterest income:
Service charges on deposit accounts	$ 99,180	$ 91,105	$ 86,020
Trust fees
Noninterest income:
Service charges on deposit accounts	89,630	71,734	67,565
Bank card and ATM fees
Noninterest income:
Service charges on deposit accounts	86,135	85,491	82,966
Investment and annuity fees and insurance commissions
Noninterest income:
Service charges on deposit accounts	49,162	43,424	36,714
Secondary mortgage market operations
Noninterest income:
Service charges on deposit accounts	$ 14,769	$ 12,374	$ 9,159