Consolidated Statements of Changes in Stockholders' Equity (Parentheticals) - $ / shares	3 Months Ended
	Jun. 30, 2018	Mar. 31, 2018	Jun. 30, 2017	Mar. 31, 2017
Cash dividends declared per common share (in dollars per share)	$ 0.06		$ 0.05
Common Stock [Member]
Cash dividends declared per common share (in dollars per share)	$ 0.06	$ 0.06	$ 0.05	$ 0.05
Issuance of shares of common stock as a result of stock purchased under the Employee Stock Purchase Plan (in shares)	5,728	2,669	4,582	3,573
Issuance of shares of common stock as s result of stock options exercised (in shares)	26,641	13,074	8,027	44,284
Restricted stock awards (in shares)	3,972	6,860	2,000	13,289
Exchange of shares of common stock in connection with stock options exercised and restricted stock vested (in shares)	642	3,814	594	6,772