Segment Information (Segment Financial Information) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Segment Reporting Information [Line Items]
Net Interest Income	$ 24,813	$ 24,671	$ 49,538	$ 45,455
Net Gains on Sales of Loans	959	883	1,646	1,603
Net Gains on Securities	0	968	0	968
Trust and Investment Product Fees	1,350	1,223	2,593	2,244
Insurance Revenues	1,744	1,605	4,384	4,332
Noncash Items:
Provision for Loan Losses	350	350	850	1,200
Depreciation and Amortization	1,190	1,179	2,317	2,227
Income Tax Expense (Benefit)	3,425	4,249	7,246	6,014
Segment Profit (Loss)	9,839	9,788	19,395	14,934
Segment Assets	3,004,803		3,004,803		$ 2,955,994
Operating Segments | Core Banking
Segment Reporting Information [Line Items]
Net Interest Income	24,999	24,873	49,908	45,771
Net Gains on Sales of Loans	959	883	1,646	1,603
Net Gains on Securities	0	968	0	968
Trust and Investment Product Fees	1	2	2	3
Insurance Revenues	12	4	14	8
Noncash Items:
Provision for Loan Losses	350	350	850	1,200
Depreciation and Amortization	1,103	1,089	2,144	2,064
Income Tax Expense (Benefit)	3,615	4,419	7,237	6,100
Segment Profit (Loss)	9,791	9,800	18,756	14,881
Segment Assets	3,001,898		3,001,898		2,958,585
Operating Segments | Trust and Investment Advisory Services
Segment Reporting Information [Line Items]
Net Interest Income	1	1	2	0
Net Gains on Sales of Loans	0	0	0	0
Net Gains on Securities	0	0	0	0
Trust and Investment Product Fees	1,350	1,221	2,594	2,241
Insurance Revenues	8	5	13	13
Noncash Items:
Provision for Loan Losses	0	0	0	0
Depreciation and Amortization	4	1	7	2
Income Tax Expense (Benefit)	49	50	83	64
Segment Profit (Loss)	66	76	110	83
Segment Assets	1,907		1,907		1,851
Operating Segments | Insurance
Segment Reporting Information [Line Items]
Net Interest Income	2	1	4	3
Net Gains on Sales of Loans	0	0	0	0
Net Gains on Securities	0	0	0	0
Trust and Investment Product Fees	0	0	0	0
Insurance Revenues	1,724	1,596	4,357	4,311
Noncash Items:
Provision for Loan Losses	0	0	0	0
Depreciation and Amortization	19	25	38	51
Income Tax Expense (Benefit)	48	58	475	568
Segment Profit (Loss)	74	87	747	877
Segment Assets	9,774		9,774		8,494
Other
Segment Reporting Information [Line Items]
Net Interest Income	(189)	(204)	(376)	(319)
Net Gains on Sales of Loans	0	0	0	0
Net Gains on Securities	0	0	0	0
Trust and Investment Product Fees	(1)	0	(3)	0
Insurance Revenues	0	0	0	0
Noncash Items:
Provision for Loan Losses	0	0	0	0
Depreciation and Amortization	64	64	128	110
Income Tax Expense (Benefit)	(287)	(278)	(549)	(718)
Segment Profit (Loss)	(92)	$ (175)	(218)	$ (907)
Segment Assets	$ (8,776)		$ (8,776)		$ (12,936)