Note 3 - Allowance for Loan Losses, Nonperforming Assets and Impaired Loans - Nonperforming Assets (Details) - USD ($) $ in Thousands		Mar. 31, 2018		Dec. 31, 2017		Mar. 31, 2017
Nonperforming assets:
Nonaccrual loans		$ 6		$ 6		$ 1,040
Restructured loans in nonaccrual		2,758		2,763		4,640
Total nonperforming loans		2,764	[1],[2]	2,769	[1],[2]	5,680
Other real estate owned, net		2,741		2,817		2,952
Total nonperforming assets		$ 5,505		$ 5,586		$ 8,632
Ratio of nonperforming assets to loans, net of unearned income and deferred fees and costs, plus other real estate owned		0.83%		0.83%		1.32%
Ratio of allowance for loan losses to nonperforming loans(1)	[3]	267.40%		286.20%		145.44%

[1] Includes current and past due loans in nonaccrual status. Includes impaired loans in nonaccrual status.

[2] Only classes with past-due or nonaccrual loans are shown.

[3] The Company defines nonperforming loans as nonaccrual loans and restructured loans that are nonaccrual. Nonperforming loans do not include loans 90 days past due and still accruing or accruing restructured loans.