Consolidated Statements of Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Interest income
Loans	$ 91,798	$ 83,371	$ 79,884
Federal funds sold	491	263	292
Mortgage loans held for sale	237	249	174
Taxable	8,451	8,120	7,565
Tax-exempt	1,195	1,167	1,172
Total interest income	102,172	93,170	89,087
Interest expense
Deposits	3,943	3,739	4,321
Securities sold under agreements to repurchase	136	149	140
Federal funds purchased	76	25	29
Federal Home Loan Bank advances	763	939	840
Total interest expense	4,918	4,852	5,330
Net interest income	97,254	88,318	83,757
Provision (credit) for loan losses	3,000	750	(400)
Net interest income after provision for loan losses	94,254	87,568	84,157
Non-interest income
Wealth management and trust services	19,155	18,026	18,212
Service charges on deposit accounts	9,471	8,906	8,883
Bankcard transactions	5,655	4,876	4,673
Mortgage banking	3,897	3,488	2,653
Securities brokerage	2,145	1,994	2,060
Bank owned life insurance	871	889	927
Other	2,343	1,771	1,747
Total non-interest income	43,537	39,950	39,155
Non-interest expenses
Salaries and employee benefits	49,185	44,709	44,687
Net occupancy	6,279	5,912	5,963
Data processing	7,073	6,348	6,393
Furniture and equipment	1,143	1,074	1,016
FDIC insurance	1,181	1,258	1,314
(Gain) Loss on other real estate owned	(409)	147	(271)
Amortization of investment in tax credit partnerships	4,458	634	1,095
Other	12,610	13,316	13,012
Total non-interest expenses	81,520	73,398	73,209
Income before income taxes	56,271	54,120	50,103
Income tax expense	15,244	16,933	15,281
Net income	$ 41,027	$ 37,187	$ 34,822
Net income per share, basic (in dollars per share)	$ 1.84	$ 1.68	$ 1.59
Net income per share, diluted (in dollars per share)	$ 1.80	$ 1.65	$ 1.57