GOODWILL AND OTHER INTANGIBLE ASSETS (Details) - USD ($) $ in Thousands		12 Months Ended
	May 18, 2018	Dec. 31, 2019	Dec. 31, 2018	Oct. 01, 2018	May 31, 2018	Aug. 31, 2016	Apr. 29, 2016	Dec. 05, 2014
Goodwill		$ 19,574	$ 22,024	$ 19,574
Deposit based intangible assets		5,043	5,720	6,746
Amortization expense		677	450
Future Amortization Expense		675
Amortization expense year one		675
Amortization expense year two		675
Amortization expense year three		675
Amortization expense year four		675
Amortization expense year five		675
PFC
Goodwill								$ 3,805
Deposit based intangible assets		594	714					$ 1,206
Amortization expense		121	121
Future Amortization Expense		121
Eagle River
Goodwill							$ 1,839
Deposit based intangible assets		629	728				$ 993
Amortization expense		99	99
Future Amortization Expense		99
Niagara Bancorporation
Goodwill						$ 50
Deposit based intangible assets		200	230			$ 300
Amortization expense		30	30
Future Amortization Expense		30
FFNM
Increase deferred tax asset		1,950
Increase to MSRs	$ 500
Decrease Goodwill		2,450
Goodwill	12,628				$ 12,628
Deposit based intangible assets	$ 2,894	2,436	2,735
Amortization expense		299	159
Future Amortization Expense		290
Lincoln Community Bank
Decrease deferred tax liability		163
Decrease Goodwill		163
Goodwill				1,252
Deposit based intangible assets		1,184	1,313	$ 1,353
Amortization expense		128	$ 41
Future Amortization Expense		$ 135