Consolidated Statements of Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Interest income:
Loans, including fees	$ 186,870	$ 172,333	$ 561,990	$ 487,668
Securities:
Taxable	32,122	21,339	87,125	63,085
Tax-exempt	57,328	59,200	175,067	173,209
Interest-bearing deposits	8,759	14,445	27,226	42,456
Federal funds sold and resell agreements	1,194	1,399	4,323	3,575
Total interest income	286,273	268,716	855,731	769,993
Interest expense:
Deposits	25,637	22,201	79,655	50,414
Federal funds purchased and repurchase agreements	5,040	2,292	15,276	3,557
Junior subordinated deferrable interest debentures	1,425	1,394	4,401	3,847
Other long-term borrowings	1,164	1,164	3,492	3,492
Total interest expense	33,266	27,051	102,824	61,310
Net interest income	253,007	241,665	752,907	708,683
Provision for loan losses	8,001	2,650	25,404	17,846
Net interest income after provision for loan losses	245,006	239,015	727,503	690,837
Non-interest income:
Trust and investment management fees	31,649	30,801	93,794	89,509
Service charges on deposit accounts	22,941	21,569	65,529	63,554
Insurance commissions and fees	11,683	11,037	40,207	37,573
Interchange and debit card transaction fees	4,117	3,499	11,265	10,103
Other charges, commissions and fees	10,108	9,580	28,103	27,860
Net gain (loss) on securities transactions	96	(34)	265	(113)
Other	8,630	11,205	29,484	35,682
Total non-interest income	89,224	87,657	268,647	264,168
Non-interest expense:
Salaries and wages	93,812	87,547	277,078	259,434
Employee benefits	21,002	18,355	64,579	58,257
Net occupancy	24,202	19,894	64,602	59,089
Technology, furniture and equipment	22,415	21,004	66,236	61,142
Deposit insurance	2,491	4,694	7,752	14,178
Intangible amortization	274	336	904	1,093
Other	44,668	41,838	132,722	125,994
Total non-interest expense	208,864	193,668	613,873	579,187
Income before income taxes	125,366	133,004	382,277	375,818
Income taxes	13,530	15,160	42,359	40,153
Net income	111,836	117,844	339,918	335,665
Preferred stock dividends	2,016	2,016	6,047	6,047
Net income available to common shareholders	$ 109,820	$ 115,828	$ 333,871	$ 329,618
Earnings per common share:
Basic	$ 1.74	$ 1.80	$ 5.28	$ 5.13
Diluted	$ 1.73	$ 1.78	$ 5.24	$ 5.08