Consolidated Statements of Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Interest Income:
Interest and fees on loans and leases	$ 621,028	$ 552,441	$ 511,612
Taxable interest and dividends on securities	180,346	190,061	189,408
Non-taxable interest on securities	19,090	15,948	17,064
Loans held for sale	1,449	1,590	857
Total interest income	821,913	760,040	718,941
Interest Expense:
Deposits	49,858	46,031	44,162
Securities sold under agreements to repurchase and other borrowings	14,528	16,861	19,388
Federal Home Loan Bank advances	29,033	22,858	16,909
Long-term debt	9,981	9,665	10,041
Total interest expense	103,400	95,415	90,500
Net interest income	718,513	664,625	628,441
Provision for loan and lease losses	56,350	49,300	37,250
Net interest income (loss) after provision for loan and lease losses	662,163	615,325	591,191
Non-interest Income:
Deposit service fees	140,685	135,057	103,431
Loan and lease related fees	30,113	25,594	23,212
Wealth and investment services	28,962	32,486	34,946
Mortgage banking activities	11,103	7,795	4,070
Increse in cash surrender value of life insurance policies	14,759	13,020	13,178
Gain on sale of investment securities, net	414	609	5,499
Impairment loss on securities recognized in earnings	(149)	(110)	(1,145)
Other income	38,591	23,326	18,917
Total non-interest income	264,478	237,777	202,108
Non-interest Expense:
Compensation and benefits	331,726	297,517	270,151
Occupancy	60,294	48,836	47,325
Technology and equipment	79,882	80,813	61,993
Intangible assets amortization	5,652	6,340	2,685
Marketing	19,703	16,053	15,379
Professional and outside services	14,801	11,156	8,296
Deposit insurance	26,006	24,042	22,670
Other expense	85,127	70,584	73,101
Total non-interest expense	623,191	555,341	501,600
Income before income tax expense	303,450	297,761	291,699
Income tax expense	96,323	93,032	91,973
Net income	207,127	204,729	199,726
Preferred stock dividends and other	(8,704)	(9,368)	(11,230)
Earnings applicable to common shareholders	$ 198,423	$ 195,361	$ 188,496
Earnings per common share:
Earnings per common share, Basic (in dollars per share)	$ 2.17	$ 2.15	$ 2.10
Earnings per common share, Diluted (in dollars per share)	$ 2.16	$ 2.13	$ 2.08