Consolidated Statements of Stockholders' Equity Parenthetical - $ / shares	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Statement of Stockholders' Equity [Abstract]
Cash Dividends Paid, per Share, in dollars per share	$ 0.25	$ 0.243
Exercised, in shares	27,662	16,721
Shares Issued Under Directors Stock Plan, in shares		554
Shares Issued Under Employee Stock Purchase Plan, in shares	3,674	3,049
Shares Issued for Dividend Reinvestment Plans - Shares	12,459	12,447
Purchase of Treasury Stock, in shares	18,715	33,970