Stock Based Compensation Schedule of Other Stock Option Plan Information (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Granted, in shares	55,621	58,349.5	58,975.431
Fair Value of Options Granted, Weighted Average Grant Date, in dollars per share	$ 6.25	$ 5.44	$ 5.34
Dividend Yield	2.72%	3.88%	3.90%
Expected Volatility	21.40%	32.95%	33.55%
Risk Free Interest Rate	2.25%	1.80%	1.57%
Expected Life, in years	6 years 10 months 16 days	7 years 6 months 21 days	7 years 7 months 28 days
Stock-Based Compensation Expense	$ 351	$ 287	$ 308
Compensation Costs for Non-vested Awards Not Yet Recognized	$ 528	$ 521	$ 500
Weighted Average Expected Vesting Period, In Years	2 years 7 months 2 days	2 years 8 months 15 days	2 years 1 month 15 days
Proceeds From Stock Options Exercised	$ 1,190	$ 2,404	$ 918
Tax Benefit for Exercises of Stock Options	168	188	59
Intrinsic Value of Stock Options Exercised	$ 825	$ 1,010	$ 250