Note 12 - Subsequent Events (Details Textual) - Subsequent Event [Member] $ in Millions	Oct. 21, 2020 USD ($)
The 4.00% Subordinated Notes [Member]
Proceeds from Issuance of Debt	$ 34.8
Debt Instrument, Interest Rate, Stated Percentage	4.00%
The 5.00% Subordinated Notes [Member]
Debt Instrument, Interest Rate, Stated Percentage	5.00%

The cash inflow during the period from additional borrowings in aggregate debt. Includes proceeds from short-term and long-term debt.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3255-108585

Name:	us-gaap_ProceedsFromIssuanceOfDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration