Consolidated Statements of Income (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Interest income:
Loans, including fees	$ 213,713	$ 238,723
Loans held for sale	671	621
Securities-taxable	31,203	32,607
Securities-tax exempt	4,783	4,944
Short-term investments	415	448
Total interest income	250,785	277,343
Interest expense:
Deposits	9,227	38,937
Short-term borrowings	1,533	4,462
Long-term debt	5,438	2,756
Total interest expense	16,198	46,155
Net interest income	234,587	231,188
Provision for credit losses	(4,911)	246,793
Net interest income (loss) after provision for credit losses	239,498	(15,605)
Noninterest income:
Other income	15,652	16,179
Total noninterest income	87,089	84,387
Noninterest expense:
Compensation expense	95,846	91,071
Employee benefits	23,769	22,478
Personnel expense	119,615	113,549
Net occupancy expense	12,910	12,522
Equipment expense	4,781	4,617
Data processing expense	22,947	22,047
Professional services expense	11,251	9,741
Amortization of intangible assets	4,419	5,345
Deposit insurance and regulatory fees	3,395	5,815
Other real estate and foreclosed asset expense	6	10,130
Other expense	13,748	19,569
Total noninterest expense	193,072	203,335
Income (loss) before income taxes	133,515	(134,553)
Income taxes expense (benefit)	26,343	(23,520)
Net income (loss)	$ 107,172	$ (111,033)
Earnings (loss) per common share-basic	$ 1.21	$ (1.28)
Earnings (loss) per common share-diluted	1.21	(1.28)
Dividends paid per share	$ 0.27	$ 0.27
Weighted average shares outstanding-basic	86,752	87,186
Weighted average shares outstanding-diluted	86,805	87,186
Service charges on deposit accounts
Noninterest income:
Service charges on deposit accounts	$ 19,146	$ 22,837
Trust fees
Noninterest income:
Service charges on deposit accounts	15,003	14,806
Bank card and ATM fees
Noninterest income:
Service charges on deposit accounts	18,120	17,362
Investment and annuity fees and insurance commissions
Noninterest income:
Service charges on deposit accounts	7,458	7,150
Secondary mortgage market operations
Noninterest income:
Service charges on deposit accounts	$ 11,710	$ 6,053