Consolidated Statements of Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Interest income:
Loans, including fees	$ 172,137	$ 185,272
Securities:
Taxable	26,030	24,679
Tax-exempt	58,886	59,143
Interest-bearing deposits	8,125	10,639
Federal funds sold and resell agreements	802	1,588
Total interest income	265,980	281,321
Interest expense:
Deposits	16,053	27,174
Federal funds purchased and repurchase agreements	3,037	5,016
Junior subordinated deferrable interest debentures	1,205	1,498
Other long-term borrowings	1,164	1,164
Total interest expense	21,459	34,852
Net interest income	244,521	246,469
Credit loss expense	175,197	11,003
Net interest income after credit loss expense	69,324	235,466
Non-interest income:
Trust and investment management fees	34,473	31,697
Service charges on deposit accounts	22,651	20,790
Insurance commissions and fees	16,485	18,406
Interchange and debit card transaction fees	3,255	3,280
Other charges, commissions and fees	9,365	9,062
Net gain (loss) on securities transactions	108,989	0
Other	17,697	13,550
Total non-interest income	212,915	96,785
Non-interest expense:
Salaries and wages	98,812	92,476
Employee benefits	24,889	23,526
Net occupancy	25,384	19,267
Technology, furniture and equipment	25,240	21,664
Deposit insurance	2,624	2,808
Intangible amortization	257	325
Other	46,957	41,734
Total non-interest expense	224,163	201,800
Income before income taxes	58,076	130,451
Income taxes	3,323	13,955
Net income	54,753	116,496
Preferred stock dividends	2,016	2,016
Redemption of preferred stock	5,514	0
Net income available to common shareholders	$ 47,223	$ 114,480
Earnings per common share:
Basic	$ 0.75	$ 1.80
Diluted	$ 0.75	$ 1.79