Consolidated Statements of Changes in Shareholders' Equity (Parenthetical) - $ / shares	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Statement of Stockholders' Equity [Abstract]
Cash dividends declared (in dollars per share)	$ 0.57	$ 0.53
Exercise of stock options (in shares)	2,650	5,638
Purchase of treasury shares (in shares)	181,899	54,740