Business Acquisition - Fair Value (Details) - USD ($) $ in Thousands			12 Months Ended
	Apr. 03, 2017	Jul. 01, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Bonterra Builders, LLC
Fair value, Transaction Costs, and Goodwill
Intangibles		$ 2,000
Amortization of Intangible Assets			$ 500	$ 400	$ 300
Decrease in goodwill due to post-closing purchase price adjustments					1,700
Transaction and integration costs					$ 900
Savvy Homes
Fair value, Transaction Costs, and Goodwill
Transaction and integration costs			1,000
Trade Name | Bonterra Builders, LLC
Fair value, Transaction Costs, and Goodwill
Intangibles		$ 1,400
Amortization period (in years)		5 years
Trade Name | Savvy Homes
Fair value, Transaction Costs, and Goodwill
Intangibles	$ 407
Amortization period (in years)	2 years 9 months
Amortization of Intangible Assets			$ 100
Non-compete intangible asset | Bonterra Builders, LLC
Fair value, Transaction Costs, and Goodwill
Intangibles		$ 600
Amortization period (in years)		3 years