Segment Information (Segment Financial Information) (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Segment Reporting Information [Line Items]
Net Interest Income	$ 38,459		$ 33,641		$ 74,715	$ 67,232
Net Gains on Sales of Loans	2,654		1,030		4,517	2,011
Net Gains on Securities	993		516		1,583	671
Trust and Investment Product Fees	1,867		1,913		3,898	3,480
Insurance Revenues	1,830		1,929		5,059	5,134
Noncash Items:
Provision for Credit Losses	5,900		250		11,050	925
Depreciation and Amortization	2,367		2,063		4,708	4,073
Income Tax Expense (Benefit)	2,639		3,011		5,026	5,759
Segment Profit (Loss)	14,255	$ 12,472	15,271	$ 15,067	26,727	30,338
Segment Assets	4,851,051				4,851,051		$ 4,397,672
Operating Segments | Core Banking
Segment Reporting Information [Line Items]
Net Interest Income	39,157		34,182		76,109	68,317
Net Gains on Sales of Loans	2,654		1,030		4,517	2,011
Net Gains on Securities	993		516		1,583	671
Trust and Investment Product Fees	0		1		1	2
Insurance Revenues	2		4		5	7
Noncash Items:
Provision for Credit Losses	5,900		250		11,050	925
Depreciation and Amortization	2,268		1,976		4,511	3,903
Income Tax Expense (Benefit)	3,126		3,437		5,367	6,092
Segment Profit (Loss)	14,098		15,068		25,945	29,567
Segment Assets	4,838,682				4,838,682		4,381,945
Operating Segments | Trust and Investment Advisory Services
Segment Reporting Information [Line Items]
Net Interest Income	4		4		8	6
Net Gains on Sales of Loans	0		0		0	0
Net Gains on Securities	0		0		0	0
Trust and Investment Product Fees	1,867		1,912		3,897	3,478
Insurance Revenues	10		4		11	25
Noncash Items:
Provision for Credit Losses	0		0		0	0
Depreciation and Amortization	1		2		2	3
Income Tax Expense (Benefit)	111		128		228	204
Segment Profit (Loss)	336		372		670	587
Segment Assets	4,124				4,124		3,670
Operating Segments | Insurance
Segment Reporting Information [Line Items]
Net Interest Income	3		4		7	9
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	1,818		1,921		5,043	5,102
Noncash Items:
Provision for Credit Losses	0		0		0	0
Depreciation and Amortization	17		21		34	39
Income Tax Expense (Benefit)	40		50		400	407
Segment Profit (Loss)	127		147		1,221	1,237
Segment Assets	10,612				10,612		9,080
Other
Segment Reporting Information [Line Items]
Net Interest Income	(705)		(549)		(1,409)	(1,100)
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	0		0		0	0
Noncash Items:
Provision for Credit Losses	0		0		0	0
Depreciation and Amortization	81		64		161	128
Income Tax Expense (Benefit)	(638)		(604)		(969)	(944)
Segment Profit (Loss)	(306)		$ (316)		(1,109)	$ (1,053)
Segment Assets	$ (2,367)				$ (2,367)		$ 2,977