Amount, before accumulated depreciation, of real estate investments for entities with a substantial portion of business acquiring and holding investment real estate.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 10
-Section S99
-Paragraph 6
-Subparagraph (SX 210.5-04.(c) Schedule III)
-URI http://asc.fasb.org/extlink&oid=27047687&loc=d3e5864-122674

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 970
-SubTopic 360
-Section S99
-Paragraph 1
-Subparagraph (SX 210.12-28.4)
-URI http://asc.fasb.org/extlink&oid=6590653&loc=d3e638233-123024

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

Schedule III - Real Estate and Accumulated Depreciation (Parenthetical) (Detail) - USD ($)	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Reconciliation to Consolidated Balance Sheet at December 31, 2015
Income Properties, Land, Buildings, and Improvements	$ 268,970,875	$ 191,634,698
Total	268,970,875
Real Estate [Member]
Reconciliation to Consolidated Balance Sheet at December 31, 2015
Income Properties, Land, Buildings, and Improvements	268,970,875
Total	$ 268,970,875	$ 209,294,277	$ 170,194,285	$ 151,226,811