Note 6 - Investments - Schedule of Investments (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Investments	$ 1,498	$ 1,632
CoBank Stock, at Cost [Member]
Investments	1,192	1,311
Rental Property [Member]
Investments	219	245
Other Miscellaneous Investments [Member]
Investments	$ 87	$ 76

Sum of the carrying amounts as of the balance sheet date of all investments.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.1(h))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

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