SHAREHOLDERS' EQUITY (Details) - USD ($)		6 Months Ended	12 Months Ended
	Jun. 15, 2018	Jun. 30, 2018	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Apr. 28, 2015	Dec. 17, 2013	Feb. 27, 2013
Participation in the TARP Capital Purchase Program
Increase in shareholders equity as a result of common stock issued		$ 34,101,000
Number of shares authorized to be repurchased		25,000						$ 600,000	$ 600,000
Number of additional shares authorized to be repurchased							$ 750,000
Gross proceeds	$ 34,500,000
Net proceeds	$ 32,500,000	$ 32,524,000
Shares issued (in shares)	2,225,807
Shares of Common Stock
Participation in the TARP Capital Purchase Program
Common stocks issued for FFNM acquisition (in shares)		2,146,378
Number of shares repurchased			14,000	102,455	13,700	55,594
Shares issued (in shares)		2,225,807