Consolidated Statements of Changes in Shareholders' Equity (Unaudited) (Parenthetical) - $ / shares	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Consolidated Statements of Changes in Shareholders' Equity (Unaudited) [Abstract]
Stock options exercised (in shares)	4,000	279,000
Cash dividend declared (in dollars per share)	$ 0.0656	$ 0.0656
Purchase of treasury stock (in shares)		213,356
Sale of treasury stock (in shares)	65,289	71,925