Consolidated Statements Of Changes In Shareholders' Equity (Parenthetical) - $ / shares	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Statement of Stockholders' Equity [Abstract]
Cash dividends declared (in dollars per share)	$ 1.32	$ 1.29
Exercise of stock options (in shares)	16,639	21,000
Stock issued during period (in shares)	440,604	0
Purchase of treasury shares (in shares)	0	231,132