Note 7 - Fair Value - Schedule of Quantitative Information About Level 3 Fair Value Measurements (Details) - Fair Value, Nonrecurring [Member]	Sep. 30, 2019 USD ($)	Dec. 31, 2018 USD ($)	Sep. 30, 2018 USD ($)
Other real estate owned	$ 0	$ 160,000	$ 0
Fair Value, Inputs, Level 3 [Member]
Other real estate owned		$ 160,000
Fair Value, Inputs, Level 3 [Member] \| Measurement Input, Comparability Adjustment [Member] \| Weighted Average [Member]
Other real estate owned, measurement input		0.1

Carrying amount of other real estate not separately disclosed, including, but not limited to, real estate investments, real estate loans that qualify as investments in real estate, and premises that are no longer used in operations may also be included in real estate owned. This does not include real estate assets taken in settlement of troubled loans through surrender or foreclosure.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.10(4))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Name:	us-gaap_OtherRealEstate
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant