Note 13 - Regulatory Capital and Oversight (Details Textual) - USD ($) $ in Millions	Jan. 01, 2019	Mar. 31, 2020
Banks Tangible Assets		$ 776.7
Adjusted Assets		775.8
Banking Regulation, Risk-Weighted Assets, Actual		$ 643.7
Capital Conservation Buffer	2.50%

Amount of risk-weighted assets as defined by regulatory framework.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 505
-Section 50
-Paragraph 1
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=117337116&loc=SL5958568-112826

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