Estimated Development Liability (Details) home in Thousands, $ in Thousands	12 Months Ended
Dec. 31, 2017 USD ($) home	Dec. 31, 2016 USD ($)
Estimated Development Liability
Cash expenditures for obligations related to prior sales	$ 500
Estimated development liability	$ 31,556	$ 32,102
Minimum
Estimated Development Liability
Number of estimated homes the estimated liability covers (homesites) \| home	8

Carrying amount as of the balance sheet date of the liability for the obligation to provide retail land sale buyers with improvements.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 976
-SubTopic 330
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6497913&loc=d3e22628-108666

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