Real Estate - Real Estate Table (Detail) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Real Estate Properties [Line Items]
Real estate	$ 498,043	$ 130,380
Land and Land Improvements [Member]
Real Estate Properties [Line Items]
Real estate	495,437	127,442
Land [Member]
Real Estate Properties [Line Items]
Real estate	$ 2,606	$ 2,938

Carrying amount as of the balance sheet date, net of valuation allowances and impairment losses, of costs of land expected to be developed in the near term plus capitalized costs of development, for purposes of selling completed units to home buyers or commercial or industrial entities..

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.6(a))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant