Note 4 - Loans and Allowance for Loan Losses (Details) - Troubled Debt Restructurings, Excluding Loans Acquired, Segregated by Class of Loans $ in Thousands	3 Months Ended	9 Months Ended		12 Months Ended
	Sep. 30, 2015 USD ($)	Sep. 30, 2015 USD ($)	Sep. 30, 2014	Dec. 31, 2014 USD ($)
Consumer:
Troubled debt - Number	8	15	2
Loans, Excluding Acquired Loans [Member]
Consumer:
Troubled debt - Number		22		8
Troubled debt -Balance	$ 4,316	$ 4,316		$ 3,241
Loans, Excluding Acquired Loans [Member] | Performing Financial Instruments [Member]
Consumer:
Troubled debt - Number		5		5
Troubled debt -Balance	1,955	$ 1,955		$ 2,233
Loans, Excluding Acquired Loans [Member] | Nonperforming Financial Instruments [Member]
Consumer:
Troubled debt - Number		17		3
Troubled debt -Balance	$ 2,361	$ 2,361		$ 1,008
Consumer Portfolio Segment [Member]
Consumer:
Troubled debt - Number	1	1
Consumer Portfolio Segment [Member] | Other Loans [Member]
Consumer:
Troubled debt - Number	1	1
Consumer Portfolio Segment [Member] | Loans, Excluding Acquired Loans [Member]
Consumer:
Troubled debt - Number		1
Troubled debt -Balance	$ 13	$ 13
Consumer Portfolio Segment [Member] | Loans, Excluding Acquired Loans [Member] | Other Loans [Member]
Consumer:
Troubled debt - Number		1
Troubled debt -Balance	13	$ 13
Consumer Portfolio Segment [Member] | Loans, Excluding Acquired Loans [Member] | Performing Financial Instruments [Member]
Consumer:
Troubled debt - Number		0
Troubled debt -Balance	0	$ 0
Consumer Portfolio Segment [Member] | Loans, Excluding Acquired Loans [Member] | Performing Financial Instruments [Member] | Other Loans [Member]
Consumer:
Troubled debt - Number		0
Troubled debt -Balance	0	$ 0
Consumer Portfolio Segment [Member] | Loans, Excluding Acquired Loans [Member] | Nonperforming Financial Instruments [Member]
Consumer:
Troubled debt - Number		1
Troubled debt -Balance	13	$ 13
Consumer Portfolio Segment [Member] | Loans, Excluding Acquired Loans [Member] | Nonperforming Financial Instruments [Member] | Other Loans [Member]
Consumer:
Troubled debt - Number		1
Troubled debt -Balance	$ 13	$ 13
Commercial Real Estate Portfolio Segment [Member]
Consumer:
Troubled debt - Number	7	14	1
Commercial Real Estate Portfolio Segment [Member] | Single Family Residential Loans [Member]
Consumer:
Troubled debt - Number	2	8	1
Commercial Real Estate Portfolio Segment [Member] | Loans, Excluding Acquired Loans [Member]
Consumer:
Troubled debt - Number		21		8
Troubled debt -Balance	$ 4,303	$ 4,303		$ 3,241
Commercial Real Estate Portfolio Segment [Member] | Loans, Excluding Acquired Loans [Member] | Other Loans [Member]
Consumer:
Troubled debt - Number		9		4
Troubled debt -Balance	2,755	$ 2,755		$ 2,454
Commercial Real Estate Portfolio Segment [Member] | Loans, Excluding Acquired Loans [Member] | Construction Loans [Member]
Consumer:
Troubled debt - Number		1		1
Troubled debt -Balance	256	$ 256		$ 391
Commercial Real Estate Portfolio Segment [Member] | Loans, Excluding Acquired Loans [Member] | Single Family Residential Loans [Member]
Consumer:
Troubled debt - Number		11		3
Troubled debt -Balance	1,292	$ 1,292		$ 396
Commercial Real Estate Portfolio Segment [Member] | Loans, Excluding Acquired Loans [Member] | Performing Financial Instruments [Member]
Consumer:
Troubled debt - Number		5		5
Troubled debt -Balance	1,955	$ 1,955		$ 2,233
Commercial Real Estate Portfolio Segment [Member] | Loans, Excluding Acquired Loans [Member] | Performing Financial Instruments [Member] | Other Loans [Member]
Consumer:
Troubled debt - Number		3		3
Troubled debt -Balance	1,818	$ 1,818		$ 1,840
Commercial Real Estate Portfolio Segment [Member] | Loans, Excluding Acquired Loans [Member] | Performing Financial Instruments [Member] | Construction Loans [Member]
Consumer:
Troubled debt - Number		0		0
Troubled debt -Balance	0	$ 0		$ 0
Commercial Real Estate Portfolio Segment [Member] | Loans, Excluding Acquired Loans [Member] | Performing Financial Instruments [Member] | Single Family Residential Loans [Member]
Consumer:
Troubled debt - Number		2		2
Troubled debt -Balance	137	$ 137		$ 393
Commercial Real Estate Portfolio Segment [Member] | Loans, Excluding Acquired Loans [Member] | Nonperforming Financial Instruments [Member]
Consumer:
Troubled debt - Number		16		3
Troubled debt -Balance	2,348	$ 2,348		$ 1,008
Commercial Real Estate Portfolio Segment [Member] | Loans, Excluding Acquired Loans [Member] | Nonperforming Financial Instruments [Member] | Other Loans [Member]
Consumer:
Troubled debt - Number		6		1
Troubled debt -Balance	937	$ 937		$ 614
Commercial Real Estate Portfolio Segment [Member] | Loans, Excluding Acquired Loans [Member] | Nonperforming Financial Instruments [Member] | Construction Loans [Member]
Consumer:
Troubled debt - Number		1		1
Troubled debt -Balance	256	$ 256		$ 391
Commercial Real Estate Portfolio Segment [Member] | Loans, Excluding Acquired Loans [Member] | Nonperforming Financial Instruments [Member] | Single Family Residential Loans [Member]
Consumer:
Troubled debt - Number		9		1
Troubled debt -Balance	$ 1,155	$ 1,155		$ 3