Organization Limited Liability Companies (LLCs) and Limited Partnerships (LPs) (Details)	6 Months Ended
Jun. 30, 2018
Rangers Sub I, LLC
Real Estate Properties [Line Items]
Limited Liability Company or Limited Partnership, Members or Limited Partners, Ownership Interest	99.00%
Rangers General Partner, LLC [Member]
Real Estate Properties [Line Items]
Limited Liability Company or Limited Partnership, Members or Limited Partners, Ownership Interest	1.00%

Percentage investment held by members or limited partners of limited liability company (LLC) or limited partnership (LP).

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 272
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70478-108055

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