Note 3 - Loans - Loans Individually Evaluated for Impairment (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2017	Dec. 31, 2016
Loans with no related allowance recorded, recorded investment	$ 3,385	$ 3,609
Loans with no related allowance recorded, unpaid principal balance	4,535	4,392
Loans with no related allowance recorded, average recorded investment	3,498	4,996
Loans with an allowance recorded, recorded investment	2,702	2,660
Loans with an allowance recorded, unpaid principal balance	3,175	3,135
Related allowance	1,188	1,267
Loans with an allowance recorded, average recorded investment	2,680	2,567
Recorded investment	6,087	6,269
Unpaid principal balance	7,710	7,527
Average recorded investment	6,178	7,563
Commercial and Industrial Portfolio Segment [Member]
Loans with no related allowance recorded, recorded investment	199	322
Loans with no related allowance recorded, unpaid principal balance	708	465
Loans with no related allowance recorded, average recorded investment	261	1,947
Loans with an allowance recorded, recorded investment	2,644	2,360
Loans with an allowance recorded, unpaid principal balance	3,117	2,835
Related allowance	1,130	1,207
Loans with an allowance recorded, average recorded investment	2,501	1,619
Recorded investment	2,843	2,682
Unpaid principal balance	3,825	3,300
Average recorded investment	2,762	3,566
Construction and Development Excluding Undeveloped Land Portfolio Segment [Member]
Loans with no related allowance recorded, recorded investment	444	538
Loans with no related allowance recorded, unpaid principal balance	614	708
Loans with no related allowance recorded, average recorded investment	491	108
Loans with an allowance recorded, recorded investment
Loans with an allowance recorded, unpaid principal balance
Related allowance
Loans with an allowance recorded, average recorded investment		182
Recorded investment	444	538
Unpaid principal balance	614	708
Average recorded investment	491	290
Undevelopment Land Portfolio Segment [Member]
Loans with no related allowance recorded, recorded investment	474	233
Loans with no related allowance recorded, unpaid principal balance	507	265
Loans with no related allowance recorded, average recorded investment	353	76
Loans with an allowance recorded, recorded investment		241
Loans with an allowance recorded, unpaid principal balance		241
Related allowance		1
Loans with an allowance recorded, average recorded investment	121	149
Recorded investment	474	474
Unpaid principal balance	507	506
Average recorded investment	474	225
Real Estate Mortgage Portfolio Segment [Member]
Loans with no related allowance recorded, recorded investment	2,268	2,516
Loans with no related allowance recorded, unpaid principal balance	2,706	2,954
Loans with no related allowance recorded, average recorded investment	2,393	2,847
Loans with an allowance recorded, recorded investment
Loans with an allowance recorded, unpaid principal balance
Related allowance
Loans with an allowance recorded, average recorded investment		554
Recorded investment	2,268	2,516
Unpaid principal balance	2,706	2,954
Average recorded investment	2,393	3,401
Real Estate Mortgage Portfolio Segment [Member] | Commercial Investment [Member]
Loans with no related allowance recorded, recorded investment	169	107
Loans with no related allowance recorded, unpaid principal balance	169	107
Loans with no related allowance recorded, average recorded investment	138	193
Loans with an allowance recorded, recorded investment
Loans with an allowance recorded, unpaid principal balance
Related allowance
Loans with an allowance recorded, average recorded investment
Recorded investment	169	107
Unpaid principal balance	169	107
Average recorded investment	138	193
Real Estate Mortgage Portfolio Segment [Member] | Owner Occupied Commercial [Member]
Loans with no related allowance recorded, recorded investment	1,236	1,042
Loans with no related allowance recorded, unpaid principal balance	1,674	1,479
Loans with no related allowance recorded, average recorded investment	1,139	1,356
Loans with an allowance recorded, recorded investment
Loans with an allowance recorded, unpaid principal balance
Related allowance
Loans with an allowance recorded, average recorded investment		554
Recorded investment	1,236	1,042
Unpaid principal balance	1,674	1,479
Average recorded investment	1,139	1,910
Real Estate Mortgage Portfolio Segment [Member] | One to Four Family Residential [Member]
Loans with no related allowance recorded, recorded investment	688	984
Loans with no related allowance recorded, unpaid principal balance	688	985
Loans with no related allowance recorded, average recorded investment	792	980
Loans with an allowance recorded, recorded investment
Loans with an allowance recorded, unpaid principal balance
Related allowance
Loans with an allowance recorded, average recorded investment
Recorded investment	688	984
Unpaid principal balance	688	985
Average recorded investment	792	980
Real Estate Mortgage Portfolio Segment [Member] | Home Equity First Lien [Member]
Loans with no related allowance recorded, recorded investment
Loans with no related allowance recorded, unpaid principal balance
Loans with no related allowance recorded, average recorded investment		3
Loans with an allowance recorded, recorded investment
Loans with an allowance recorded, unpaid principal balance
Related allowance
Loans with an allowance recorded, average recorded investment
Recorded investment
Unpaid principal balance
Average recorded investment		3
Real Estate Mortgage Portfolio Segment [Member] | Home Equity Junior Lien [Member]
Loans with no related allowance recorded, recorded investment	175	383
Loans with no related allowance recorded, unpaid principal balance	175	383
Loans with no related allowance recorded, average recorded investment	324	315
Loans with an allowance recorded, recorded investment
Loans with an allowance recorded, unpaid principal balance
Related allowance
Loans with an allowance recorded, average recorded investment
Recorded investment	175	383
Unpaid principal balance	175	383
Average recorded investment	324	315
Consumer Portfolio Segment [Member]
Loans with no related allowance recorded, recorded investment
Loans with no related allowance recorded, unpaid principal balance
Loans with no related allowance recorded, average recorded investment		18
Loans with an allowance recorded, recorded investment	58	59
Loans with an allowance recorded, unpaid principal balance	58	59
Related allowance	58	59
Loans with an allowance recorded, average recorded investment	58	63
Recorded investment	58	59
Unpaid principal balance	58	59
Average recorded investment	$ 58	$ 81