Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Interest income:
Loans, including fees	$ 940,629	$ 825,862	$ 907,290
Loans held for sale	1,814	2,543	2,622
Securities-taxable	166,731	131,382	127,629
Securities-tax exempt	18,847	18,969	19,454
Short-term investments	9,042	3,502	986
Total interest income	1,137,063	982,258	1,057,981
Interest expense:
Deposits	58,439	26,246	88,261
Short-term borrowings	16,191	6,015	10,042
Long-term debt	12,430	16,762	17,155
Total interest expense	87,060	49,023	115,458
Net interest income	1,050,003	933,235	942,523
Provision for credit losses	(28,399)	(77,494)	602,904
Net interest income after provision for credit losses	1,078,402	1,010,729	339,619
Noninterest income:
Securities transactions	(87)	333	488
Other income	53,911	74,801	56,385
Total noninterest income	331,486	364,334	324,428
Noninterest expense:
Compensation expense	378,482	378,589	379,727
Employee benefits	82,153	103,786	84,332
Personnel expense	460,635	482,375	464,059
Net occupancy expense	48,767	49,786	52,589
Equipment expense	18,573	18,167	19,212
Data processing expense	103,942	96,755	87,823
Professional services expense	36,065	48,678	49,529
Amortization of intangibles	14,033	16,665	19,916
Deposit insurance and regulatory fees	14,889	13,582	18,804
Other real estate and foreclosed assets expense (income)	(4,407)	(210)	9,555
Other expense	58,195	81,209	67,305
Total noninterest expense	750,692	807,007	788,792
Income (loss) before income taxes	659,196	568,056	(124,745)
Income tax expense (benefit)	135,107	104,841	(79,571)
Net income (loss)	$ 524,089	$ 463,215	$ (45,174)
Earnings (loss) per common share - basic	$ 6.00	$ 5.23	$ (0.54)
Earnings (loss) per common share - diluted	5.98	5.22	(0.54)
Dividends paid per share	$ 1.08	$ 1.08	$ 1.08
Weighted average shares outstanding - basic	86,068	86,823	86,533
Weighted average shares outstanding - diluted	86,394	87,027	86,533
Service charges on deposit accounts
Noninterest income:
Service charges on deposit accounts	$ 87,663	$ 81,032	$ 76,659
Trust fees
Noninterest income:
Service charges on deposit accounts	65,132	62,898	58,191
Bank card and ATM fees
Noninterest income:
Service charges on deposit accounts	84,591	79,074	68,131
Investment and annuity fees and insurance commissions
Noninterest income:
Service charges on deposit accounts	28,752	29,502	24,330
Secondary mortgage market operations
Noninterest income:
Service charges on deposit accounts	$ 11,524	$ 36,694	$ 40,244