Note 8 - Mortgages and Other Financing Receivables (Details Textual) $ in Millions, $ in Millions	9 Months Ended
Sep. 30, 2018 USD ($)	Sep. 30, 2018 CAD ($)
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Number of Loans	11	11
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Ending Balance	$ 29.2
Mortgage Receivable [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Collections of Principal	4.5	$ 5.7
Operating Properties [Member]
Proceeds from Sale of Real Estate, Total	20.8
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, New Mortgage Loan	$ 14.7
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Interest Rate	5.16%	5.16%
Operating Properties [Member] \| London Interbank Offered Rate (LIBOR) [Member]
Loans Receivable, Basis Spread on Variable Rate	3.00%
Operating Properties [Member] \| Minimum [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Interest Rate	5.00%	5.00%

Amount of decrease in 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, from collection of principal.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 12
-Footnote 6
-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 6))
-URI http://asc.fasb.org/extlink&oid=6589523&loc=d3e617274-123014

+ Details

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Namespace Prefix:	srt_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Interest rate of mortgage loan 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.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 12
-Paragraph Column B
-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(Column B))
-URI http://asc.fasb.org/extlink&oid=6589523&loc=d3e617274-123014

+ Details

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Namespace Prefix:	srt_
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Balance Type:	na
Period Type:	duration

- Definition

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.

+ References

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

+ Details

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

- Definition

The percentage points (also referred to as 'margin') added to the reference rate as stated in the loan agreement and used to compute the variable rate on the loans receivable. For instance, the loan agreement might state that the interest rate the borrower is obligated to pay is the London Interbank Offered Rate (LIBOR) plus three quarters (3/4) of a percentage point adjusted quarterly (each three months). LIBOR in this example is the index or reference rate, 3/4 percentage point is the margin, the reference rate plus the margin is the fully indexed rate. This element would be used to report separately the margin.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of 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.

+ References

Reference 1: 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(Column G))
-URI http://asc.fasb.org/extlink&oid=6589523&loc=d3e617274-123014

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

- Definition

Amount of increase in mortgage loan on real estate by entity with substantial portion of business acquiring and holding investment real estate or interest in real estate, from new investment.

+ References

Reference 1: 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 6))
-URI http://asc.fasb.org/extlink&oid=6589523&loc=d3e617274-123014

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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- Definition

Cash received for the sale of real estate that is not part of an investing activity during the current period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3179-108585

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- Details

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- Details

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Balance Type:
Period Type:

- Details

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Namespace Prefix:
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