Consolidated Statements of Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Interest income:
Loans, including fees	$ 168,779	$ 169,002	$ 518,957	$ 512,444
Securities:
Taxable	20,736	22,560	61,366	71,950
Tax-exempt	56,882	58,073	169,656	175,968
Interest-bearing deposits	5,830	1,512	11,877	10,894
Federal funds sold	2	5	13	721
Resell agreements	6	14	11	163
Total interest income	252,235	251,166	761,880	772,140
Interest expense:
Deposits	3,677	5,397	10,693	27,677
Federal funds purchased	9	7	24	92
Repurchase agreements	632	475	1,597	3,913
Junior subordinated deferrable interest debentures	631	700	1,915	2,893
Subordinated notes	1,164	1,164	3,492	3,492
Federal Home Loan Bank advances	0	0	0	318
Total interest expense	6,113	7,743	17,721	38,385
Net interest income	246,122	243,423	744,159	733,755
Credit loss expense	0	20,302	63	227,474
Net interest income after credit loss expense	246,122	223,121	744,096	506,281
Non-interest income:
Trust and investment management fees	37,381	31,469	110,569	97,002
Service charges on deposit accounts	21,216	19,812	61,058	60,043
Insurance commissions and fees	11,748	11,456	39,834	38,609
Interchange and card transaction fees	4,490	3,503	13,224	9,724
Other charges, commissions and fees	9,785	8,370	26,729	25,398
Net gain (loss) on securities transactions	0	0	0	108,989
Other	8,569	8,991	26,258	34,352
Total non-interest income	93,189	83,601	277,672	374,117
Non-interest expense:
Salaries and wages	99,463	93,323	289,956	282,485
Employee benefits	21,576	16,074	62,840	59,824
Net occupancy	27,208	25,466	79,909	76,116
Technology, furniture and equipment	28,494	26,482	84,508	77,768
Deposit insurance	3,088	2,372	8,893	7,796
Intangible amortization	157	212	544	710
Other	38,017	38,221	116,749	121,293
Total non-interest expense	218,003	202,150	643,399	625,992
Income before income taxes	121,308	104,572	378,369	254,406
Income taxes	13,333	9,516	36,311	11,525
Net income	107,975	95,056	342,058	242,881
Preferred stock dividends	1,668	0	5,488	2,016
Redemption of preferred stock	0	0	0	5,514
Net income available to common shareholders	$ 106,307	$ 95,056	$ 336,570	$ 235,351
Earnings per common share:
Basic	$ 1.66	$ 1.50	$ 5.25	$ 3.72
Diluted	$ 1.65	$ 1.50	$ 5.22	$ 3.71