Real Estate - Real Estate (Details)	3 Months Ended
	Mar. 31, 2018 USD ($) Lot Project	Dec. 31, 2017 USD ($)
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Real estate | $	$ 261,707,000	$ 130,380,000
Number of Projects | Project	14
Payments to Acquire Real Estate | $	$ 130,487,000
Number of Units in Real Estate Property	13,600
Entitled, developed and under development projects
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Real estate | $	$ 258,873,000	127,442,000
Residential Real Estate [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Number of Lots Acquired	5,500
Right of First Offer [Member] | D.R. Horton, Inc. [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Number of Units in Real Estate Property	5,400
Under Contract [Member] | D.R. Horton, Inc. [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Number of Units in Real Estate Property	3,300
Under Contract [Member] | Unaffiliated Customer [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Number of Units in Real Estate Property	500
Land [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Real estate | $	$ 2,834,000	$ 2,938,000