Note 11 - Other Borrowings and Unused Lines of Credit - Unused Lines of Credit (Details) - USD ($)	Dec. 31, 2018	Dec. 31, 2017
Unused lines of credit	$ 363,690,108	$ 374,967,441
Secured Debt
Unused lines of credit	1,690,108	2,967,441
Unsecured Debt
Unused lines of credit	$ 362,000,000	$ 372,000,000

Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19(b),22(b))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Name:	us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant