INVESTMENT SECURITIES (Details) - USD ($) $ in Thousands	3 Months Ended
INVESTMENT SECURITIES (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
SECURITIES AVAILABLE FOR SALE
Increase (Decrease) In Fair Value Of Marketable Securities	$ 2,422
Amortized cost	107,337	$ 109,349
Estimated Fair Value	109,414	111,836
Available-for-sale Securities
SECURITIES AVAILABLE FOR SALE
Amortized cost	107,337	109,349
Gross Unrealized Gains	2,352	2,512
Gross Unrealized Losses	(275)	(25)
Estimated Fair Value	109,414	111,836
US Treasury
SECURITIES AVAILABLE FOR SALE
Amortized cost	1,067
Gross Unrealized Gains	3
Estimated Fair Value	1,070
Corporate
SECURITIES AVAILABLE FOR SALE
Amortized cost	29,042	27,815
Gross Unrealized Gains	304	247
Gross Unrealized Losses	(222)	(19)
Estimated Fair Value	29,124	28,043
US Agencies
SECURITIES AVAILABLE FOR SALE
Amortized cost	6,486	6,480
Gross Unrealized Gains	78	109
Estimated Fair Value	6,564	6,589
US Agencies - MBS
SECURITIES AVAILABLE FOR SALE
Amortized cost	30,389	33,372
Gross Unrealized Gains	906	914
Gross Unrealized Losses	(3)	(6)
Estimated Fair Value	31,292	34,280
Obligations of states and political subdivisions
SECURITIES AVAILABLE FOR SALE
Amortized cost	40,353	41,682
Gross Unrealized Gains	1,061	1,242
Gross Unrealized Losses	(50)
Estimated Fair Value	$ 41,364	$ 42,924

MACKINAC FINANCIAL CORP /MI/ 10-Q