Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Interest income:
Loans, including fees	$ 825,862	$ 907,290	$ 971,735
Loans held for sale	2,543	2,622	1,876
Securities-taxable	131,382	127,629	127,459
Securities-tax exempt	18,969	19,454	20,757
Short-term investments	3,502	986	3,955
Total interest income	982,258	1,057,981	1,125,782
Interest expense:
Deposits	26,246	88,261	187,988
Short-term borrowings	6,015	10,042	30,766
Long-term debt	16,762	17,155	11,811
Total interest expense	49,023	115,458	230,565
Net interest income	933,235	942,523	895,217
Provision for credit losses	(77,494)	602,904	47,708
Net interest income after provision for credit losses	1,010,729	339,619	847,509
Noninterest income:
Securities transactions, net	333	488
Other income	74,801	56,385	54,531
Total noninterest income	364,334	324,428	315,907
Noninterest expense:
Compensation expense	378,589	379,727	362,083
Employee benefits	103,786	84,332	77,796
Personnel expense	482,375	464,059	439,879
Net occupancy expense	49,786	52,589	50,936
Equipment expense	18,167	19,212	18,393
Data processing expense	96,755	87,823	82,981
Professional services expense	48,678	49,529	45,007
Amortization of intangibles	16,665	19,916	20,844
Deposit insurance and regulatory fees	13,582	18,804	19,512
Other real estate and foreclosed assets expense (income)	(210)	9,555	671
Other expense	81,209	67,305	92,454
Total noninterest expense	807,007	788,792	770,677
Income (loss) before income taxes	568,056	(124,745)	392,739
Income tax expense (benefit)	104,841	(79,571)	65,359
Net income (loss)	$ 463,215	$ (45,174)	$ 327,380
Earnings (loss) per common share - basic	$ 5.23	$ (0.54)	$ 3.72
Earnings (loss) per common share - diluted	5.22	(0.54)	3.72
Dividends paid per share	$ 1.08	$ 1.08	$ 1.08
Weighted average shares outstanding - basic	86,823	86,533	86,488
Weighted average shares outstanding - diluted	87,027	86,533	86,599
Service charges on deposit accounts
Noninterest income:
Service charges on deposit accounts	$ 81,032	$ 76,659	$ 86,364
Trust fees
Noninterest income:
Service charges on deposit accounts	62,898	58,191	61,609
Bank card and ATM fees
Noninterest income:
Service charges on deposit accounts	79,074	68,131	66,976
Investment and annuity fees and insurance commissions
Noninterest income:
Service charges on deposit accounts	29,502	24,330	26,574
Secondary mortgage market operations
Noninterest income:
Service charges on deposit accounts	$ 36,694	$ 40,244	$ 19,853