Consolidated Statements of Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Interest income:
Loans, including fees	$ 138,400	$ 114,368	$ 392,073	$ 340,303
Securities:
Taxable	23,203	25,897	72,032	77,402
Tax-exempt	54,939	53,065	167,321	154,308
Interest-bearing deposits	10,800	4,111	26,712	11,366
Federal funds sold and resell agreements	244	48	514	165
Total interest income	227,586	197,489	658,652	583,544
Interest expense:
Deposits	5,668	1,749	9,709	5,309
Federal funds purchased and repurchase agreements	523	44	849	152
Junior subordinated deferrable interest debentures	1,020	839	2,890	2,392
Other long-term borrowings	1,164	350	2,696	958
Total interest expense	8,375	2,982	16,144	8,811
Net interest income	219,211	194,507	642,508	574,733
Provision for loan losses	10,980	5,045	27,358	42,734
Net interest income after provision for loan losses	208,231	189,462	615,150	531,999
Non-interest income:
Trust and investment management fees	27,493	26,451	81,690	77,806
Service charges on deposit accounts	20,967	20,540	62,934	60,769
Insurance commissions and fees	10,892	11,029	34,441	35,812
Interchange and debit card transaction fees	5,884	5,435	17,150	15,838
Other charges, commissions and fees	10,493	10,703	29,983	29,825
Net gain (loss) on securities transactions	(4,867)	(37)	(4,917)	14,866
Other	10,753	7,993	25,114	21,358
Total non-interest income	81,615	82,114	246,395	256,274
Non-interest expense:
Salaries and wages	84,388	79,411	247,895	236,814
Employee benefits	17,730	17,844	57,553	55,861
Net occupancy	19,391	18,202	57,781	53,631
Furniture and equipment	18,743	17,979	54,983	53,474
Deposit insurance	4,862	4,558	15,347	12,412
Intangible amortization	405	586	1,301	1,869
Other	41,304	41,925	127,929	125,048
Total non-interest expense	186,823	180,505	562,789	539,109
Income before income taxes	103,023	91,071	298,756	249,164
Income taxes	9,892	10,852	35,131	28,622
Net income	93,131	80,219	263,625	220,542
Preferred stock dividends	2,016	2,016	6,047	6,047
Net income available to common shareholders	$ 91,115	$ 78,203	$ 257,578	$ 214,495
Earnings per common share:
Basic	$ 1.43	$ 1.24	$ 4.02	$ 3.44
Diluted	$ 1.41	$ 1.24	$ 3.98	$ 3.42