Consolidated Statements of Stockholders' Equity (unaudited) (Parenthetical) - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Consolidated Statements of Stockholders' Equity (unaudited) [Abstract]
Cash dividends - per share (in dollars per share)	$ 0.28	$ 0.27	$ 0.82	$ 0.81
Purchase of treasury shares (in shares)	119,342		400,000	263,507
Net issuance of shares to employee benefit plans and other stock plans (in shares)	1,672	3,030	108,599	78,276