Condensed Consolidated Statements of Changes in Stockholders' Equity (Unaudited) (Parentheticals) - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Common dividends declared, per share (in dollars per share)	$ 0.27	$ 0.25	$ 0.77	$ 0.75
Issuance of stock to 401(k) plan, shares (in shares)	3,967	6,237	13,118	18,148
Common stock options exercised, shares (in shares)	9,371		19,773
Repurchase of common shares, shares (in shares)	277,386		726,686	734,653
Repurchase of common shares, per share (in dollars per share)	$ 30.52		$ 29.49	$ 29.77