Parent Company Financial Information, Condensed Statements of Cash Flows (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Cash Flows from Operating Activities [Abstract]
Net Income	$ 29,723	$ 27,392	$ 25,402
Adjustments to Reconcile Net Income to Net Cash Provided by Operating Activities [Abstract]
Net Cash Provided by Operating Activities	34,812	37,327	26,415
Investing Activities [Abstract]
Net Cash Used by Investing Activities	(185,444)	(258,308)	(279,430)
Financing Activities [Abstract]
Cash Dividends	(10,478)	(10,157)	(9,919)
Net Cash Provided by Financing Activities	190,046	203,302	246,463
Increase (Decrease) in Cash and Cash Equivalents	39,414	(17,679)	(6,552)
Parent Company [Member]
Cash Flows from Operating Activities [Abstract]
Net Income	29,723	27,392	25,402
Adjustments to Reconcile Net Income to Net Cash Provided by Operating Activities [Abstract]
Equity in Undistributed Net Earnings from Subsidiary	(17,043)	(17,352)	(18,211)
Net (Increase) Decrease in Other Assets	(124)	(79)	(114)
Net Increase (Decrease) in Liabilities	49	141	(1)
Net Cash Provided by Operating Activities	12,605	10,102	7,076
Investing Activities [Abstract]
Payments for Business Acquisition	(2,207)	0	0
Payments for Investments in Subsidiaries	(2,586)	(3,360)	0
Net Cash Used by Investing Activities	(4,793)	(3,360)	0
Financing Activities [Abstract]
Issuance of Common Stock	2,586	3,360	2,790
Cash Dividends	(10,478)	(10,157)	(9,919)
Net Cash Provided by Financing Activities	(7,892)	(6,797)	(7,129)
Increase (Decrease) in Cash and Cash Equivalents	(80)	(55)	(53)
Cash and Cash Equivalents at Beginning of Year	308	363	416
Cash and Cash Equivalents at End of Year	$ 228	$ 308	$ 363