Consolidated Statements of Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Interest income:
Loans, including fees	$ 185,272	$ 151,202
Securities:
Taxable	24,679	20,558
Tax-exempt	59,143	56,711
Interest-bearing deposits	10,639	14,094
Federal funds sold and resell agreements	1,588	761
Total interest income	281,321	243,326
Interest expense:
Deposits	27,174	10,638
Federal funds purchased and repurchase agreements	5,016	634
Junior subordinated deferrable interest debentures	1,498	1,142
Other long-term borrowings	1,164	1,164
Total interest expense	34,852	13,578
Net interest income	246,469	229,748
Provision for loan losses	11,003	6,945
Net interest income after provision for loan losses	235,466	222,803
Non-interest income:
Trust and investment management fees	31,697	29,587
Service charges on deposit accounts	20,790	20,843
Insurance commissions and fees	18,406	15,980
Interchange and debit card transaction fees	3,280	3,158
Other charges, commissions and fees	9,062	9,007
Net gain (loss) on securities transactions	0	(19)
Other	13,550	12,889
Total non-interest income	96,785	91,445
Non-interest expense:
Salaries and wages	92,476	86,683
Employee benefits	23,526	21,995
Net occupancy	19,267	19,740
Technology, furniture and equipment	21,664	19,679
Deposit insurance	2,808	4,879
Intangible amortization	325	388
Other	41,734	43,247
Total non-interest expense	201,800	196,611
Income before income taxes	130,451	117,637
Income taxes	13,955	11,157
Net income	116,496	106,480
Preferred stock dividends	2,016	2,016
Net income available to common shareholders	$ 114,480	$ 104,464
Earnings per common share:
Basic	$ 1.80	$ 1.63
Diluted	$ 1.79	$ 1.61