Consolidated Statements of Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
INTEREST INCOME
Loans	$ 135,150	$ 112,724	$ 261,284	$ 219,284
Securities:
Taxable interest	20,523	18,441	40,303	37,631
Tax-exempt interest	18,290	18,296	36,993	35,479
Total securities income	38,813	36,737	77,296	73,110
Federal funds and resell agreements	752	711	1,790	1,630
Interest-bearing due from banks	1,056	580	2,636	1,131
Trading securities	709	459	1,139	746
Total interest income	176,480	151,211	344,145	295,901
INTEREST EXPENSE
Deposits	18,334	7,835	32,169	13,801
Federal funds and repurchase agreements	6,666	4,994	11,398	8,463
Other	1,254	988	2,430	1,928
Total interest expense	26,254	13,817	45,997	24,192
Net interest income	150,226	137,394	298,148	271,709
Provision for loan losses	7,000	14,500	17,000	23,500
Net interest income after provision for loan losses	143,226	122,894	281,148	248,209
NONINTEREST INCOME
Trading and investment banking	4,653	6,173	8,754	13,715
Gain on sales of securities available for sale, net	228	1,280	367	1,748
Other	8,026	8,675	18,627	15,191
Total noninterest income	100,289	110,306	205,814	213,223
NONINTEREST EXPENSE
Salaries and employee benefits	104,175	102,773	212,143	206,425
Occupancy, net	10,813	11,061	21,766	22,029
Equipment	18,842	17,956	37,668	35,438
Supplies and services	4,146	4,792	7,906	8,886
Marketing and business development	6,184	5,732	11,218	9,873
Processing fees	11,537	10,743	22,698	19,942
Legal and consulting	6,460	6,467	10,304	11,517
Bankcard	4,165	5,033	8,791	9,936
Amortization of other intangible assets	1,485	1,924	3,047	3,970
Regulatory fees	3,772	4,071	6,677	7,904
Other	5,639	6,387	10,876	14,829
Total noninterest expense	177,218	176,939	353,094	350,749
Income before income taxes	66,297	56,261	133,868	110,683
Income tax expense	10,873	11,490	20,911	23,936
Income from continuing operations	55,424	44,771	112,957	86,747
Discontinued Operations
(Loss) income from discontinued operations before income taxes		(2,599)	(917)	308
Income tax (benefit) expense		(649)	(170)	53
(Loss) income from discontinued operations		(1,950)	(747)	255
NET INCOME	$ 55,424	$ 42,821	$ 112,210	$ 87,002
Basic:
Income from continuing operations	$ 1.12	$ 0.91	$ 2.28	$ 1.76
(Loss) income from discontinued operations		(0.04)	(0.01)	0.01
Net income – basic	1.12	0.87	2.27	1.77
Diluted:
Income from continuing operations	1.11	0.90	2.26	1.74
(Loss) income from discontinued operations		(0.04)	(0.01)	0.01
Net income - diluted	1.11	0.86	2.25	1.75
Dividends	$ 0.290	$ 0.255	$ 0.580	$ 0.510
Weighted average shares outstanding - basic	49,551,920	49,269,786	49,486,626	49,190,271
Weighted average shares outstanding - diluted	50,007,022	49,848,903	49,973,992	49,829,193
Trust and Securities Processing [Member]
NONINTEREST INCOME
Noninterest income	$ 42,845	$ 44,811	$ 86,847	$ 87,352
Service Charges On Deposit Accounts [Member]
NONINTEREST INCOME
Noninterest income	20,722	22,731	42,627	44,806
Insurance Fees and Commissions [Member]
NONINTEREST INCOME
Noninterest income	340	513	641	1,159
Brokerage Fees [Member]
NONINTEREST INCOME
Noninterest income	6,291	5,889	12,644	11,266
Bankcard Fees [Member]
NONINTEREST INCOME
Noninterest income	$ 17,184	$ 20,234	$ 35,307	$ 37,986