Consolidated Statements of Stockholders' Equity (Parentheticals) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Unallocated ESOP Shares [Member]
Allocation of ESOP shares (in shares)	18,779	18,779
Common Stock [Member]
Offering expenses		$ 1,627,317
Shares repurchased (in shares)	17,600
Retained Earnings [Member]
Cash dividends paid, per share (in dollars per share)	$ 0.16