Stockholder's Equity Parenthetical (Parentheticals) - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement of Stockholders' Equity [Abstract]
Cash Dividends Paid, per Share	$ 1.00	$ 0.95	$ 0.92
Stock Dividends - Shares	554,264	538,100	522,425
Stock Options Exercised - Shares	105,055	57,756	109,651
Shares Issued Under Directors Stock Plan - Shares	5,601	6,828	6,005
Shares Issued Under the Employee Stock Purchase Plan - Shares	14,832	15,028	17,113
Shares Issued for Dividend Reinvestment Plans - Shares	49,714	49,605	55,432
Purchase of Treasury Stock - Shares	58,527	96,496	72,723
Allocation of ESOP Stock - Shares	4,931	10,407	36,927