Consolidated Statements of Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Interest income:
Loans, including fees	$ 114,368	$ 111,087	$ 340,303	$ 324,858
Securities:
Taxable	25,897	27,518	77,402	85,607
Tax-exempt	53,065	49,518	154,308	144,117
Interest-bearing deposits	4,111	1,937	11,366	5,743
Federal funds sold and resell agreements	48	28	165	69
Total interest income	197,489	190,088	583,544	560,394
Interest expense:
Deposits	1,749	2,138	5,309	7,076
Federal funds purchased and repurchase agreements	44	39	152	113
Junior subordinated deferrable interest debentures	839	689	2,392	2,016
Other long-term borrowings	350	241	958	696
Total interest expense	2,982	3,107	8,811	9,901
Net interest income	194,507	186,981	574,733	550,493
Provision for loan losses	5,045	6,810	42,734	17,845
Net interest income after provision for loan losses	189,462	180,171	531,999	532,648
Non-interest income:
Trust and investment management fees	26,451	25,590	77,806	79,223
Service charges on deposit accounts	20,540	20,854	60,769	60,664
Insurance commissions and fees	11,029	11,763	35,812	36,528
Interchange and debit card transaction fees	5,435	5,031	15,838	14,591
Other charges, commissions and fees	10,703	10,016	29,825	28,570
Net gain (loss) on securities transactions	(37)	(52)	14,866	176
Other	7,993	10,176	21,358	25,823
Total non-interest income	82,114	83,378	256,274	245,575
Non-interest expense:
Salaries and wages	79,411	79,552	236,814	232,257
Employee benefits	17,844	16,210	55,861	53,776
Net occupancy	18,202	17,380	53,631	48,890
Furniture and equipment	17,979	16,286	53,474	47,469
Deposit insurance	4,558	3,676	12,412	10,852
Intangible amortization	586	816	1,869	2,559
Other	41,925	41,649	125,048	124,516
Total non-interest expense	180,505	175,569	539,109	520,319
Income before income taxes	91,071	87,980	249,164	257,904
Income taxes	10,852	12,130	28,622	36,814
Net income	80,219	75,850	220,542	221,090
Preferred stock dividends	2,016	2,016	6,047	6,047
Net income available to common shareholders	$ 78,203	$ 73,834	$ 214,495	$ 215,043
Earnings per common share:
Basic	$ 1.24	$ 1.18	$ 3.44	$ 3.41
Diluted	$ 1.24	$ 1.17	$ 3.42	$ 3.39