Consolidated Statements of Changes in Stockholders' Equity (Parentheticals) - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Retained Earnings [Member]
Cash dividends declared per common share (in dollars per share)	$ 0.20	$ 0.16	$ 0.08
Common Stock [Member]
Proceeds from issuance of common stock, net of issuance costs, shares (in shares)		1,215,000	3,680,000
Issuance of shares of common stock as a result of stock purchased under the Employee Stock Purchase Plan (in shares)	13,318	20,192	24,033
Issuance of shares of common stock as s result of stock options exercised (in shares)	114,100	111,423	79,638
Retirement of treasury stock, shares of common stock (in shares)			121,246
Restricted stock awards (in shares)	28,289	21,882	28,846
Exchange of shares of common stock in connection with stock options exercised and restricted stock vested (in shares)	23,054	22,735	4,631
Issuance of shares of common stock as a result of the acquisition of Guaranty Bank & Trust, net of issuance cost (in shares)	678,670
Cash dividends declared per common share (in dollars per share)	$ 0.20	$ 0.16	$ 0.08
Issuance of shares of common stock as s result of stock options exercised (in shares)	114,100	111,423	79,638