Related Party Transactions (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Related Party Transaction [Line Items]
Total related-party amounts payable	$ 726	$ 1,575
BRE Entities [Member]
Related Party Transaction [Line Items]
Total related-party amounts payable	726	582
Former Manager [Member]
Related Party Transaction [Line Items]
Total related-party amounts payable	0	993
Base management fee [Member] \| Former Manager [Member]
Related Party Transaction [Line Items]
Total related-party amounts payable	0	993
Operating expense reimbursements and direct expense reimbursements [Member] \| BRE Entities [Member]
Related Party Transaction [Line Items]
Total related-party amounts payable	568	508
Offering expense reimbursements [Member] \| BRE Entities [Member]
Related Party Transaction [Line Items]
Total related-party amounts payable	$ 158	$ 74

Carrying amount as of the balance sheet date of obligations due all related parties.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(k)(1))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.17)
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.15(3),(4))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

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