Estimated Development Liability (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018 USD ($) home	Jun. 30, 2017 USD ($)	Jun. 30, 2018 USD ($) home	Jun. 30, 2017 USD ($)	Dec. 31, 2017 USD ($)
Estimated Development Liability
Cash expenditures for obligations related to prior sales	$ 100	$ 200	$ 200	$ 300
Estimated development liability	$ 31,363		$ 31,363		$ 31,556
Minimum
Estimated Development Liability
Number of estimated homes the estimated liability covers (homesites) | home	8,000		8,000