Consolidated Statements of Changes in Shareholders' Equity (Unaudited) (Parenthetical) - $ / shares	3 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2018	Mar. 31, 2018
Consolidated Statements of Changes in Shareholders' Equity (Unaudited) [Abstract]
Cash dividend declared (in dollars per share)	$ 0.068125	$ 0.068125	$ 0.0656	$ 0.0656
Stock option exercises (in shares)		5,100	91,200	4,000
Purchase of treasury stock (in shares)		4,131	45,509
Sale of treasury stock (in shares)	76,443	86,297	70,792	65,289