Consolidated Statements of Changes in Stockholders' Equity (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement of Stockholders' Equity [Abstract]
Stock dividend, percent	3.00%	3.00%	3.00%
Treasury Stock, Shares (in shares)	4,608,258	4,558,207
Unallocated ESOP Shares (in shares)	0	5,001
Cash Dividends Paid (in dollars per share)	$ 1.02	$ 0.97	$ 0.92
Stock Dividends (in shares)	570,884	554,264	538,100
Stock Options Exercised (in shares)	84,216	105,055	57,756
Shares Issued Under Directors Stock Plan (in shares)	7,580	5,601	6,828
Shares Issued Under the Employee Stock Purchase Plan (in shares)	15,379	14,832	15,028
Shares Issued for Dividend Reinvestment Plans (in shares)	51,191	49,714	49,605
Purchase of Treasury Stock (in shares)	73,495	58,527	96,496
Allocation of ESOP Stock (in shares)	5,151	4,931	10,407