Consolidated Statements of Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
INTEREST INCOME
Loans	$ 143,947	$ 119,132	$ 405,231	$ 338,416
Securities:
Taxable interest	20,263	17,720	60,566	55,351
Tax-exempt interest	18,281	18,893	55,274	54,372
Total securities income	38,544	36,613	115,840	109,723
Federal funds and resell agreements	665	1,008	2,455	2,638
Interest-bearing due from banks	1,513	753	4,149	1,884
Trading securities	428	389	1,567	1,135
Total interest income	185,097	157,895	529,242	453,796
INTEREST EXPENSE
Deposits	25,792	10,181	57,961	23,982
Federal funds and repurchase agreements	7,524	5,811	18,922	14,274
Other	1,291	1,045	3,721	2,973
Total interest expense	34,607	17,037	80,604	41,229
Net interest income	150,490	140,858	448,638	412,567
Provision for loan losses	5,750	11,500	22,750	35,000
Net interest income after provision for loan losses	144,740	129,358	425,888	377,567
NONINTEREST INCOME
Trading and investment banking	3,711	4,453	12,465	18,168
Gain on sales of securities available for sale, net	211	2,390	578	4,138
Other	9,032	7,226	27,659	22,417
Total noninterest income	100,885	104,306	306,699	317,529
NONINTEREST EXPENSE
Salaries and employee benefits	102,956	99,749	315,099	306,174
Occupancy, net	11,628	11,285	33,394	33,314
Equipment	18,533	17,880	56,201	53,318
Supplies and services	4,528	4,076	12,434	12,962
Marketing and business development	6,671	5,056	17,889	14,929
Processing fees	12,331	11,151	35,029	31,093
Legal and consulting	8,470	5,844	18,774	17,361
Bankcard	4,407	5,130	13,198	15,066
Amortization of other intangible assets	1,385	1,715	4,432	5,685
Regulatory fees	3,337	3,798	10,014	11,702
Other	6,139	6,137	17,015	20,966
Total noninterest expense	180,385	171,821	533,479	522,570
Income before income taxes	65,240	61,843	199,108	172,526
Income tax expense	7,391	12,971	28,302	36,907
Income from continuing operations	57,849	48,872	170,806	135,619
Discontinued Operations
Loss from discontinued operations before income taxes		(1,030)	(917)	(722)
Income tax benefit		(300)	(170)	(247)
Loss from discontinued operations		(730)	(747)	(475)
NET INCOME	$ 57,849	$ 48,142	$ 170,059	$ 135,144
Basic:
Income from continuing operations	$ 1.17	$ 0.99	$ 3.45	$ 2.76
Loss from discontinued operations		(0.01)	(0.01)	(0.01)
Net income – basic	1.17	0.98	3.44	2.75
Diluted:
Income from continuing operations	1.16	0.98	3.41	2.72
Loss from discontinued operations		(0.01)	(0.01)	(0.01)
Net income - diluted	1.16	0.97	3.40	2.71
Dividends	$ 0.290	$ 0.255	$ 0.870	$ 0.765
Weighted average shares outstanding - basic	49,473,157	49,283,322	49,482,087	49,221,629
Weighted average shares outstanding - diluted	49,912,084	49,833,141	49,952,984	49,838,619
Trust and Securities Processing [Member]
NONINTEREST INCOME
Noninterest income	$ 43,425	$ 45,060	$ 130,272	$ 132,412
Service Charges On Deposit Accounts [Member]
NONINTEREST INCOME
Noninterest income	20,927	21,510	63,554	66,316
Insurance Fees and Commissions [Member]
NONINTEREST INCOME
Noninterest income	339	425	980	1,584
Brokerage Fees [Member]
NONINTEREST INCOME
Noninterest income	6,402	5,815	19,046	17,081
Bankcard Fees [Member]
NONINTEREST INCOME
Noninterest income	$ 16,838	$ 17,427	$ 52,145	$ 55,413