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