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Note 5 - Loans - Major Classifications of Loans (Details) - USD ($)	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016
Subtotal	$ 201,729,000		$ 179,231,000
Deferred loan fees	(67,000)		(74,000)
Loans in process	(6,697,000)		(6,002,000)
Allowance for loan losses	(1,908,000)	$ (1,809,000)	(1,800,000)	$ (1,519,000)	$ (1,478,000)	$ (1,478,000)
Net loans	193,057,000		171,355,000
Commercial Portfolio Segment [Member]
Subtotal	78,244,000		64,835,000
Allowance for loan losses	(806,000)	(738,000)	(660,000)	(505,000)	(468,000)	(348,000)
Commercial Portfolio Segment [Member] \| Development [Member]
Subtotal	7,275,000		1,498,000
Commercial Portfolio Segment [Member] \| Real Estate Loan [Member]
Subtotal	59,961,000		53,202,000
Commercial Portfolio Segment [Member] \| Commercial and Industrial [Member]
Subtotal	11,008,000		10,135,000
Residential Real Estate and Consumer [Member]
Subtotal	123,485,000		114,396,000
Allowance for loan losses	(1,102,000)	$ (1,071,000)	(1,140,000)	$ (1,014,000)	$ (1,010,000)	$ (1,130,000)
Residential Real Estate and Consumer [Member] \| One to Four Family Owner-occupied [Member]
Subtotal	50,604,000		47,448,000
Residential Real Estate and Consumer [Member] \| One to Four Family Investor-owned [Member]
Subtotal	32,971,000		33,658,000
Allowance for loan losses			(82,000)
Residential Real Estate and Consumer [Member] \| Multifamily Loan [Member]
Subtotal	37,953,000		31,677,000
Residential Real Estate and Consumer [Member] \| Consumer [Member]
Subtotal	$ 1,957,000		$ 1,613,000