Real Estate and Lending Activities - Schedule of Unaudited Supplemental Pro Forma Operating Data (Detail) - USD ($)	3 Months Ended	9 Months Ended
Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Business Acquisition, Pro Forma Information [Abstract]
Total revenues	$ 162,400	$ 156,500	$ 479,800	$ 480,100
Net income	$ 73,300	$ 63,000	$ 206,300	$ 227,000
Net income per share/unit - diluted	$ 0.23	$ 0.20	$ 0.64	$ 0.71

The pro forma diluted net income per share for a period as if the business combination or combinations had been completed at the beginning of a period.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(2)-(3)
-URI http://asc.fasb.org/extlink&oid=65885119&loc=d3e1392-128463

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The pro forma net Income or Loss for the period as if the business combination or combinations had been completed at the beginning of a period.

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The pro forma revenue for a period as if the business combination or combinations had been completed at the beginning of the period.

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