INCOME PROPERTIES - Properties Acquired (Details)	9 Months Ended
Sep. 30, 2018 USD ($) a ft²	Sep. 30, 2017 USD ($)
Real Estate Operations
Description of properties acquired
Purchase price		$ 40,000,000
Aspen, Colorado \| Single-tenant
Description of properties acquired
Square-Feet \| ft²	19,596
Acres \| a	0.18
Purchase price	$ 28,000,000
Percentage Leased	100.00%
Remaining Lease Term	20 years

The cash outflow from the acquisition of property as primarily intended to generate income for its owner.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 13
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3213-108585

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration