CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (Parentheticals) - USD ($)	3 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018
Cash dividends declared per common share (in dollars per share)	$ 0.06			$ 0.06
Common Stock [Member]
Cash dividends declared per common share (in dollars per share)	$ 0.06	$ 0.06	$ 0.06	$ 0.06	$ 0.06	$ 0.06
Issuance of shares of common stock as a result of stock purchased under the Employee Stock Purchase Plan (in shares)	5,674	11,346	4,446	3,205	5,728	2,669
Issuance of shares of common stock as s result of stock options exercised (in shares)	12,438	2,414	25,238	1,754	26,641	13,074
Restricted stock awards (in shares)		4,769	12,719	5,300	3,972	6,860
Exchange of shares of common stock in connection with stock options exercised and restricted stock vested (in shares)	589	1,032	5,169	9,853	642	3,814
Common Stock [Member] | Springfield Bancshares
Issuance of shares of common stock, net of issuance costs				$ 106,237
Issuance of common stock, net of issuance costs, shares (in shares)				1,699,414