Consolidated Statements of Stockholders' Equity (Parentheticals) - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Consolidated Statements of Stockholders' Equity
Shares issued under the dividend reinvestment plan ("DRP") (in shares)	39,600	24,529	25,154
Shares issued under the Employee Stock Purchase Plan ("ESPP") (in shares)	11,413	7,888	3,758
Purchase of treasury stock (in shares)	179,620	22,600
Stock awards granted and distributed (in shares)	136,662	82,210	84,910
Stock awards forfeited (in shares)	6,593	19,531	15,225
Repurchase of surrendered stock from vesting of stock plans (in shares)	95,892	26,583	17,073
Cash dividend declared (in dollars per share)	$ 0.96	$ 0.92	$ 0.92