Note 6 - Troubled Debt Restructurings - Roll Forward of TDR Loans (Details) - USD ($)		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015
Beginning Balance		$ 2,400,000
Ending Balance		1,900,000	$ 2,400,000
Performing Financial Instruments [Member]
Beginning Balance		877,000	1,422,000
Additions	[1]	92,000	0
Charge-offs	[2]	0	(8,000)
Other	[3]	(413,000)	(537,000)
Ending Balance		556,000	877,000
Nonperforming Financial Instruments [Member]
Beginning Balance		1,502,000	3,240,000
Additions	[1]		0
Charge-offs	[2]	(2,000)	(195,000)
Other	[3]	(208,000)	(1,543,000)
Ending Balance		1,384,000	1,502,000
Residential Portfolio Segment [Member] | Performing Financial Instruments [Member]
Beginning Balance		0	0
Additions		0	0
Charge-offs		0	0
Other		0	0
Ending Balance		0	0
Residential Portfolio Segment [Member] | Nonperforming Financial Instruments [Member]
Beginning Balance		809	834
Additions		0	0
Charge-offs		(2)	0
Other		(483)	(25)
Ending Balance		324	809
Commercial Portfolio Segment [Member] | Performing Financial Instruments [Member]
Beginning Balance		770,000	1,141,000
Additions	[1]	92,000	0
Charge-offs	[2]	0	(8,000)
Other	[3]	(401,000)	(363)
Ending Balance		461,000	770,000
Commercial Portfolio Segment [Member] | Nonperforming Financial Instruments [Member]
Beginning Balance		534,000	2,355,000
Additions	[1]		0
Charge-offs	[2]	0	(162,000)
Other	[3]	288,000	(1,659)
Ending Balance		822,000	534,000
Consumer Portfolio Segment [Member] | Performing Financial Instruments [Member]
Beginning Balance		107,000	281,000
Additions	[1]	0	0
Charge-offs	[2]	0	0
Other	[3]	(12,000)	(174,000)
Ending Balance		95,000	107,000
Consumer Portfolio Segment [Member] | Nonperforming Financial Instruments [Member]
Beginning Balance		159,000	51,000
Additions	[1]	92,000	0
Charge-offs	[2]	0	(33,000)
Other	[3]	(13,000)	141,000
Ending Balance		$ 238,000	$ 159,000

[1] Includes new TDRs and increases to existing TDRs.

[2] Post modification charge-offs.

[3] Includes principal payments, paydowns and performing loans previously restructured at market rates that are no longer reported as TDRs.