Consolidated Statement of Changes in Stockholders' Equity (Parentheticals) - $ / shares	3 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020
Dividends on common share (in dollars per share)	$ 0.21	$ 0.21	$ 0.21	$ 0.21	$ 0.21	$ 0.21
Common Stock [Member]
Common shares released from Employee Benefit Trust, shares (in shares)	5,493	6,445	5,682	5,015	10,956	116,414
Restricted stock unit awards vested, shares (in shares)		10,932	248,896	9,284	6,390	272,946
Treasury Stock [Member]
Purchase of treasury shares (in shares)	285,643			40,000		142,405
Repurchase of shares to satisfy tax obligation, shares (in shares)		3,886	70,292	0	2,558	74,145