Note 3 - Allowance for Loan Losses, Nonperforming Assets and Impaired Loans - Impaired Loans, Average Investment and Interest Income (Details) - USD ($) $ in Thousands		6 Months Ended			12 Months Ended
		Jun. 30, 2017		Jun. 30, 2016	Dec. 31, 2016
Average recorded investment in impaired loans(1)	[1],[2]	$ 12,017		$ 14,147	$ 11,585	[3]
Interest income recognized on impaired loans, after designation as impaired		192		149	553	[3]
Real Estate Construction Portfolio Segment[Member] | Construction, 1-4 Family Residential [Member]
Average recorded investment in impaired loans(1)	[2],[3]	3,335		678	462
Interest income recognized on impaired loans, after designation as impaired	[3]	89		0	10
Consumer Real Estate Portfolio Segment [Member] | Closed End First Liens [Member]
Average recorded investment in impaired loans(1)	[2],[3]	603		664	642
Interest income recognized on impaired loans, after designation as impaired	[3]	18		20	38
Consumer Real Estate Portfolio Segment [Member] | Closed End Junior Liens [Member]
Average recorded investment in impaired loans(1)	[2],[3]	190		213	207
Interest income recognized on impaired loans, after designation as impaired	[3]	6		7	13
Consumer Real Estate Portfolio Segment [Member] | Investor Owned Residential Real Estate [Member]
Average recorded investment in impaired loans(1)	[2],[3]	335		75	74
Interest income recognized on impaired loans, after designation as impaired	[3]	2		2	4
Commercial Real Estate Portfolio Segment [Member] | Multifamily Real Estate [Member]
Average recorded investment in impaired loans(1)	[2],[3]	887		1,595	1,366
Interest income recognized on impaired loans, after designation as impaired	[3]			0	12
Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate, Owner Occupied [Member]
Average recorded investment in impaired loans(1)	[2],[3]	3,777		4,807	4,342
Interest income recognized on impaired loans, after designation as impaired	[3]	77		120	206
Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Other [Member]
Average recorded investment in impaired loans(1)	[2],[3]	2,681		5,203	3,947
Interest income recognized on impaired loans, after designation as impaired	[3]				263
Commercial Non Real Estate Segment [Member] | Commercial and Industrial [Member]
Average recorded investment in impaired loans(1)	[2],[3]	207		912	541
Interest income recognized on impaired loans, after designation as impaired	[3]			$ 0	7
Consumer Non Real Estate Portfolio Segment [Member] | Automobile Loan [Member]
Average recorded investment in impaired loans(1)		2	[2]		4
Interest income recognized on impaired loans, after designation as impaired		$ 0			$ 0	[3]

[1] Recorded investment is net of charge-offs and interest paid while a loan is in nonaccrual status.

[2] Recorded investment is net of charge-offs and interest paid while a loan is in nonaccrual status.

[3] Only classes with impaired loans are shown.