CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (Parentheticals) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash dividends declared per common share (in dollars per share)	$ 0.24	$ 0.24	$ 0.20
Issuance of shares of common stock as a result of stock purchased under the Employee Stock Purchase Plan (in shares)	28,775
Issuance of shares of common stock as s result of stock options exercised (in shares)	59,393	60,127	114,100
Exchange of shares of common stock in connection with stock options exercised and restricted stock vested (in shares)	7,547
Bates Companies [Member]
Issuance of common stock, net of issuance costs, shares (in shares)		23,501
Retained Earnings [Member]
Cash dividends declared per common share (in dollars per share)	$ 0.24	$ 0.24	$ 0.20
Common Stock [Member]
Issuance of shares of common stock as a result of stock purchased under the Employee Stock Purchase Plan (in shares)		15,528	13,318
Issuance of shares of common stock as s result of stock options exercised (in shares)	59,393		114,100
Restricted stock awards (in shares)	19,869	22,660	28,289
Exchange of shares of common stock in connection with stock options exercised and restricted stock vested (in shares)		21,190	23,054
Common Stock [Member] | Guaranty Bank and Trust Company [Member]
Issuance of shares of common stock, net of issuance costs			$ 138,071
Issuance of shares of common stock as a result of the acquisition, net of issuance cost (in shares)			678,000
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
Common Stock [Member] | Bates Companies [Member]
Issuance of common stock, net of issuance costs, shares (in shares)	9,400
Issuance of shares of common stock as a result of the acquisition, net of issuance cost (in shares)		23,501