Note 10 - Mortgages and Other Financing Receivables (Details Textual)	12 Months Ended
Dec. 31, 2018
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Number of Loans	10

Number of mortgage loans within investment in mortgage loan on real estate by entity with substantial portion of business acquiring and holding investment real estate or interest in real estate.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 12
-Footnote 3
-Subsection 29

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 948
-SubTopic 310
-Section S99
-Paragraph 1
-Subparagraph (SX 210.12-29(Footnote 3))
-URI http://asc.fasb.org/extlink&oid=6589523&loc=d3e617274-123014

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Namespace Prefix:	srt_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration