Consolidated Statements of Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Interest income:
Loans, including fees	$ 131,073	$ 113,349	$ 253,673	$ 225,935
Securities:
Taxable	23,527	25,531	48,829	51,505
Tax-exempt	55,435	50,910	112,382	101,243
Interest-bearing deposits	9,076	3,602	15,912	7,255
Federal funds sold and resell agreements	163	59	270	117
Total interest income	219,274	193,451	431,066	386,055
Interest expense:
Deposits	2,173	1,773	4,041	3,560
Federal funds purchased and repurchase agreements	187	52	326	108
Junior subordinated deferrable interest debentures	962	803	1,870	1,553
Other long-term borrowings	1,164	321	1,532	608
Total interest expense	4,486	2,949	7,769	5,829
Net interest income	214,788	190,502	423,297	380,226
Provision for loan losses	8,426	9,189	16,378	37,689
Net interest income after provision for loan losses	206,362	181,313	406,919	342,537
Non-interest income:
Trust and investment management fees	27,727	26,021	54,197	51,355
Service charges on deposit accounts	21,198	19,865	41,967	40,229
Insurance commissions and fees	9,728	9,360	23,549	24,783
Interchange and debit card transaction fees	5,692	5,381	11,266	10,403
Other charges, commissions and fees	9,898	10,069	19,490	19,122
Net gain (loss) on securities transactions	(50)	0	(50)	14,903
Other	6,887	7,321	14,361	13,365
Total non-interest income	81,080	78,017	164,780	174,160
Non-interest expense:
Salaries and wages	80,995	78,106	163,507	157,403
Employee benefits	18,198	17,712	39,823	38,017
Net occupancy	19,153	18,242	38,390	35,429
Furniture and equipment	18,250	17,978	36,240	35,495
Deposit insurance	5,570	4,197	10,485	7,854
Intangible amortization	438	619	896	1,283
Other	45,447	42,591	86,625	83,123
Total non-interest expense	188,051	179,445	375,966	358,604
Income before income taxes	99,391	79,885	195,733	158,093
Income taxes	13,838	8,378	25,239	17,770
Net income	85,553	71,507	170,494	140,323
Preferred stock dividends	2,015	2,015	4,031	4,031
Net income available to common shareholders	$ 83,538	$ 69,492	$ 166,463	$ 136,292
Earnings per common share:
Basic	$ 1.30	$ 1.12	$ 2.59	$ 2.19
Diluted	$ 1.29	$ 1.11	$ 2.57	$ 2.19