Note 5 - Allowance for Loan Losses, Nonperforming Assets and Impaired Loans (Details) - Impaired Loans, Average Investment and Interest Income Recognized - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Real Estate Construction(2)
Average recorded investment	[1],[2]	$ 17,297	$ 16,311	$ 16,654
Interest income recognized	[1]	769	473	267
Closed-end First Liens [Member]
Real Estate Construction(2)
Average recorded investment	[1],[2]	681	555	364
Interest income recognized	[1]	43	31	3
Closed-end Junior Liens [Member]
Real Estate Construction(2)
Average recorded investment	[1],[2]	228	249	280
Interest income recognized	[1]	15	16	9
Investor-owned Residential Real Estate [Member]
Real Estate Construction(2)
Average recorded investment	[1],[2]	76	77	131
Interest income recognized	[1]	5	5	6
Multifamily Real Estate [Member]
Real Estate Construction(2)
Average recorded investment	[1],[2]	2,581	2,773	4,172
Interest income recognized	[1]	84	0	0
Commercial Real Estate, Owner Occupied [Member]
Real Estate Construction(2)
Average recorded investment	[1],[2]	6,141	5,836	5,265
Interest income recognized	[1]	251	203	136
Commercial Real Estate, Other [Member]
Real Estate Construction(2)
Average recorded investment	[1],[2]	5,888	6,114	3,369
Interest income recognized	[1]	308	175	110
Commercial and Industrial [Member]
Real Estate Construction(2)
Average recorded investment	[1],[2]	1,090	707	117
Interest income recognized	[1]	40	$ 43	3
Construction Residential [Member]
Real Estate Construction(2)
Average recorded investment	[1],[2]			40
Interest income recognized	[1]			0
Construction Other [Member]
Real Estate Construction(2)
Average recorded investment	[1],[2]			2,885
Interest income recognized	[1]			0
Automobile Loan [Member]
Real Estate Construction(2)
Average recorded investment	[1],[2]			31
Interest income recognized	[1]			$ 0
Real Estate Construction Portfolio Segment[Member] | Construction, 1-4 Family Residential [Member]
Real Estate Construction(2)
Average recorded investment	[1],[2]	612
Interest income recognized	[1]	$ 23

[1] Only classes with impaired loans are shown.

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