Consolidated Statements of Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Interest and Dividend Income
Loans, including fees	$ 70,737	$ 56,019	$ 53,035
Loans held-for-sale	123	151	189
Securities:
Taxable	10,202	15,865	14,037
Tax exempt	5,939	842	542
Dividends from Federal Reserve Bank and Federal Home Loan Bank stock	370	333	306
Interest bearing deposits with financial institutions	134	169	55
Total interest and dividend income	87,505	73,379	68,164
Interest Expense
Savings, NOW, and money market deposits	950	789	734
Time deposits	4,227	3,640	3,201
Other short-term borrowings	758	106	33
Junior subordinated debentures	4,002	4,334	4,287
Senior notes	2,689	112
Subordinated debt		949	814
Notes payable and other borrowings		8	7
Total interest expense	12,626	9,938	9,076
Net interest and dividend income	74,879	63,441	59,088
Loan loss reserve release	1,800	750	(4,400)
Net interest and dividend income after release for loan losses	73,079	62,691	63,488
Noninterest Income
Trust income	6,203	5,670	5,953
Service charges on deposits	6,720	6,684	6,820
Secondary mortgage fees	776	1,038	907
Mortgage servicing rights mark to market loss	(802)	(919)	(1,141)
Mortgage servicing gain / (loss), net of changes in fair value	1,778	1,724	1,628
Net gain on sales of mortgage loans	4,803	6,343	5,775
Securities loss, net	474	(2,213)	(178)
Increase in cash surrender value of bank-owned life insurance	1,432	1,283	1,277
Death benefit realized on bank-owned life insurance			115
Debit card interchange income	4,200	4,027	4,028
(Loss) gain on disposal and transfer of fixed assets	10	(1)	(1,119)
Other income	4,778	4,938	5,229
Total noninterest income	30,372	28,574	29,294
Noninterest Expense
Salaries and employee benefits	40,080	36,234	35,061
Occupancy expense, net	5,951	6,063	6,260
Furniture and equipment expense	4,387	4,349	4,357
FDIC insurance	658	865	1,334
General bank insurance	1,031	1,109	1,273
Amortization of core deposit intangible	96	16
Advertising expense	1,505	1,633	1,340
Debit card interchange expense	1,329	1,455	1,514
Legal fees	650	800	1,175
Other real estate expense, net	2,165	2,743	5,191
Other expense	11,297	11,494	10,916
Total noninterest expense	69,149	66,761	68,421
Income before income taxes	34,302	24,504	24,361
Provision for income taxes	19,164	8,820	8,976
Net income	15,138	15,684	15,385
Preferred stock dividends and accretion of discount			1,873
Net income available to common stockholders	$ 15,138	$ 15,684	$ 13,512
Basic earnings per share (in dollars per share)	$ 0.51	$ 0.53	$ 0.46
Diluted earnings per share (in dollars per share)	$ 0.50	$ 0.53	$ 0.46