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	$ 259,219	$ 246,015	$ 231,469
Interest and dividends on investment securities:
Taxable	32,160	30,861	29,900
Exempt from federal taxes	3,447	3,998	4,357
Interest on deposits in banks	2,589	1,537	1,334
Interest on federal funds sold	11	12	7
Total interest income	297,426	282,423	267,067
Interest expense:
Interest on deposits	12,662	13,107	13,779
Interest on securities sold under repurchase agreements	429	231	237
Interest on long-term debt	1,815	2,300	2,016
Interest on subordinated debentures held by subsidiary trusts	2,755	2,422	2,574
Total interest expense	17,661	18,060	18,606
Net interest income	279,765	264,363	248,461
Provision for loan losses	9,991	6,822	(6,622)
Net interest income after provision for loan losses	269,774	257,541	255,083
Non-interest income:
Income from the origination and sale of loans	37,222	29,973	23,940
Payment Services Revenue	34,374	32,750	30,695
Wealth management revenues	20,460	19,907	18,996
Service charges on deposit accounts	18,426	17,031	16,567
Other service charges, commissions and fees	11,506	10,404	10,047
Investment securities gains, net	330	137	61
Other income	10,028	11,313	11,529
Gain (Loss) Related to Litigation Settlement	4,150	0	0
Total non-interest income	136,496	121,515	111,835
Non-interest expense:
Salaries and wages	108,684	101,451	96,513
Employee benefits	35,193	31,324	30,564
Occupancy, net	17,714	17,879	17,796
Furniture and equipment	9,584	15,524	13,816
Outsourced technology services	20,547	10,124	9,423
FDIC insurance premiums	4,548	4,858	4,608
Professional fees	4,990	6,458	4,882
OREO expense, net of income	(44)	(1,475)	(272)
Mortgage servicing rights amortization	2,957	2,434	2,361
Mortgage servicing rights impairment recovery	(35)	(97)	(136)
Core deposit intangibles amortization	3,427	3,388	2,251
Other expenses	50,625	50,936	47,480
Loss Contingency Expense	0	5,000	4,000
Acquisition Expense	2,821	795	4,017
Total non-interest expense	261,011	248,599	237,303
Income before income tax expense	145,259	130,457	129,615
Income tax expense	49,623	43,662	45,214
Net income	$ 95,636	$ 86,795	$ 84,401
Basic earnings per common share	$ 2.15	$ 1.92	$ 1.89
Diluted earnings per common share	$ 2.13	$ 1.90	$ 1.87