Consolidated Statements of Changes In Stockholders' Equity Parenthetical - $ / shares	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Statement of Stockholders' Equity [Abstract]
Common Stock Dividends, in shares	554,264	538,100
Cash Dividends Paid, per Share, in dollars per share	$ 0.728	$ 0.707
Exercised, in shares	91,979	34,489
Shares Issued Under Directors Stock Plan, in shares	2,705	3,927
Shares Issued Under Employee Stock Purchase Plan, in shares	10,801	10,869
Shares Issued for Dividend Reinvestment Plans - Shares	35,947	37,525
Purchase of Treasury Stock, in shares	50,697	83,256