Fair Value - Additional Information (Details) - USD ($)	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017
Fair Value Disclosures [Abstract]
Valuation allowance on real estate owned	$ 0	$ 53,000	$ 78,000
Valuation allowance on impaired financing receivable	$ 1,924,000	$ 1,531,000	$ 356,000

The valuation allowance loss on real estate owned or any impairment losses taken against real estate investments held for use or resale.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 35
-Paragraph 43
-URI http://asc.fasb.org/extlink&oid=29634951&loc=d3e1739-110224

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.10(4))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 35
-Paragraph 17
-URI http://asc.fasb.org/extlink&oid=29634951&loc=d3e1424-110224

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