Number of properties disposed.

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- Definition

Organization consolidation and presentation of financial statements.

+ References

No definition available.

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- Definition

Represents the percentage of annual assumed average rent increases used as an unobservable input to measure the fair value.

+ References

No definition available.

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- Definition

Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 45
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=68055307&loc=d3e2420-110228

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585

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- Definition

Period the instrument, asset or liability is expected to be outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (bbb)
-URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258

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Ratio of the net operating income produced by an asset and its capital cost (original prices paid to buy the asset), used as an input to measure fair value.

+ References

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Interest rate used to find the present value of an amount to be paid or received in the future as an input to measure fair value. For example, but not limited to, weighted average cost of capital (WACC), cost of capital, cost of equity and cost of debt.

+ References

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- Definition

The net gain (loss) resulting from sales and other disposals of real estate owned for investment purposes.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 225
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04.14(d))
-URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882

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- Definition

Fair value portion of physical assets used in the normal conduct of business to produce goods and services and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19190-110258

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Accounting Policies - Additional Information (Detail)	3 Months Ended		6 Months Ended
Accounting Policies - Additional Information (Detail)	Jun. 30, 2018 USD ($)	Jun. 30, 2017 USD ($)	Jun. 30, 2018 USD ($) Property	Jun. 30, 2017 USD ($)
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Impairment charges	$ 1,160,000	$ 914,000	$ 3,977,000	$ 4,651,000
Number of properties disposed \| Property			6
Gain on dispositions of real estate	3,016,000	507,000	$ 3,665,000	176,000
Level 3 [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Assumed annual average rent increases for unobservable inputs			2.00%
Rate of income capitalization for unobservable inputs			8.00%
Cash flows discounted rate for unobservable inputs			7.00%
Level 3 [Member] \| Maximum [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Assumed holding periods for unobservable inputs			15 years
Estimated Sale Price Method [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Impairment charges			$ 3,977,000
Estimated fair value	2,338,000		2,338,000
Discounted Cash Flow Method [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Impairment charges			3,977,000
Estimated fair value	104,000		104,000
Accumulation of Asset Retirement Cost Method [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Impairment charges			3,977,000
Estimated fair value	1,535,000		1,535,000
Notes and Mortgages Receivable [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Impairment charges	0	0	0	0
Direct Financing Leases Financing Receivable [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Impairment charges	$ 0	$ 0	$ 0	$ 0