Consolidated Statements of Income (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Interest income:
Loans, including fees	$ 220,392	$ 243,875	$ 688,032	$ 725,390
Loans held for sale	833	592	2,104	1,189
Securities-taxable	30,863	32,724	95,172	94,107
Securities-tax exempt	4,831	5,058	14,629	15,715
Short-term investments	124	915	791	3,424
Total interest income	257,043	283,164	800,728	839,825
Interest expense:
Deposits	14,783	49,220	76,349	145,201
Short-term borrowings	1,673	7,729	8,388	23,658
Long-term debt	5,404	3,276	11,754	8,905
Total interest expense	21,860	60,225	96,491	177,764
Net interest income	235,183	222,939	704,237	662,061
Provision for credit losses	24,999	12,421	578,690	38,552
Net interest income (loss) after provision for credit losses	210,184	210,518	125,547	623,509
Noninterest income:
Other income	14,799	16,325	44,112	40,773
Total noninterest income	83,748	83,230	242,078	232,983
Noninterest expense:
Compensation expense	97,095	93,858	286,922	265,573
Employee benefits	20,761	18,622	64,892	57,240
Personnel expense	117,856	112,480	351,814	322,813
Net occupancy expense	13,191	13,156	39,272	38,101
Equipment expense	5,355	4,685	14,724	13,706
Data processing expense	21,888	21,532	65,185	60,951
Professional services expense	14,372	17,704	35,098	35,537
Amortization of intangible assets	4,788	4,889	15,302	15,074
Deposit insurance and regulatory fees	4,108	3,995	15,039	14,156
Other real estate and foreclosed asset (income) expense	(482)	2,055	9,188	1,459
Other expense	14,698	33,058	50,026	71,024
Total noninterest expense	195,774	213,554	595,648	572,821
Income (loss) before income taxes	98,158	80,194	(228,023)	283,671
Income taxes expense (benefit)	18,802	12,387	(79,274)	48,423
Net income (loss)	$ 79,356	$ 67,807	$ (148,749)	$ 235,248
Earnings (loss) per common share-basic	$ 0.90	$ 0.77	$ (1.73)	$ 2.69
Earnings (loss) per common share-diluted	0.90	0.77	(1.73)	2.69
Dividends paid per share	$ 0.27	$ 0.27	$ 0.81	$ 0.81
Weighted average shares outstanding-basic	86,358	86,377	86,614	85,934
Weighted average shares outstanding-diluted	86,400	86,462	86,614	86,010
Service charges on deposit accounts
Noninterest income:
Service charges on deposit accounts	$ 18,440	$ 21,892	$ 56,795	$ 62,982
Trust fees
Noninterest income:
Service charges on deposit accounts	14,424	15,098	43,390	46,126
Bank card and ATM fees
Noninterest income:
Service charges on deposit accounts	17,222	17,154	50,541	49,063
Investment and annuity fees and insurance commissions
Noninterest income:
Service charges on deposit accounts	5,988	7,048	18,504	20,167
Secondary mortgage market operations
Noninterest income:
Service charges on deposit accounts	$ 12,875	$ 5,713	$ 28,736	$ 13,872