Note 14 - Financial Instruments - Assets Recorded at Fair Value on a Nonrecurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Impaired Loans [Member]
Assets at fair value	$ 203	$ 371
Fair Value, Nonrecurring [Member]
Assets at fair value	203	1,124
Fair Value, Nonrecurring [Member] | Fair Value, Inputs, Level 1 [Member]
Assets at fair value
Fair Value, Nonrecurring [Member] | Fair Value, Inputs, Level 2 [Member]
Assets at fair value
Fair Value, Nonrecurring [Member] | Fair Value, Inputs, Level 3 [Member]
Assets at fair value	203	1,124
Fair Value, Nonrecurring [Member] | Impaired Loans [Member]
Assets at fair value	203	371
Fair Value, Nonrecurring [Member] | Impaired Loans [Member] | Fair Value, Inputs, Level 1 [Member]
Assets at fair value
Fair Value, Nonrecurring [Member] | Impaired Loans [Member] | Fair Value, Inputs, Level 2 [Member]
Assets at fair value
Fair Value, Nonrecurring [Member] | Impaired Loans [Member] | Fair Value, Inputs, Level 3 [Member]
Assets at fair value	$ 203	371
Fair Value, Nonrecurring [Member] | Foreclosed Assets [Member]
Assets at fair value		753
Fair Value, Nonrecurring [Member] | Foreclosed Assets [Member] | Fair Value, Inputs, Level 1 [Member]
Assets at fair value
Fair Value, Nonrecurring [Member] | Foreclosed Assets [Member] | Fair Value, Inputs, Level 2 [Member]
Assets at fair value
Fair Value, Nonrecurring [Member] | Foreclosed Assets [Member] | Fair Value, Inputs, Level 3 [Member]
Assets at fair value		$ 753