Note 11 - Federal Income Taxes (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Deferred Tax Assets, Valuation Allowance	$ 157,000	$ 270,000
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount	(100,000)	(200,000)
Deferred Tax Assets, Capital Loss Carryforwards	157,000	270,000
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued	0	0
Unrecognized Tax Benefits	0	$ 0
Firstbank Corporation [Member]
Deferred Tax Assets, Capital Loss Carryforwards	$ 500,000