Business Acquisition - Purchase Price Consideration and Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands				12 Months Ended
	Dec. 31, 2017	Apr. 03, 2017	Jul. 01, 2015	Dec. 31, 2017	Dec. 31, 2015	Dec. 31, 2016
Business Acquisitions
Contingent consideration (earn-out)				$ 1,818	$ 6,000
Assets
Goodwill	$ 30,290			$ 30,290		$ 19,285
Savvy Homes
Business Acquisitions
Cash payments to acquire businesses		$ 41,150
Total consideration		42,968
Assets
Receivables and other assets		159
Land and other inventories		39,311
Property, plant and equipment		168
Goodwill		11,005
Total assets acquired		51,050
Liabilities
Accounts payable		7,692
Accrued and other liabilities		390
Total liabilities assumed		8,082
Total net assets acquired		42,968
Bonterra Builders, LLC
Business Acquisitions
Cash payments to acquire businesses			$ 40,818
Debt repaid at closing			52,941
Total consideration			99,759
Assets
Receivables and other assets			574
Land and other inventories			91,632
Property, plant and equipment			14
Intangibles			2,000
Goodwill			13,223
Total assets acquired			107,443
Liabilities
Accounts payable			5,071
Accrued and other liabilities			763
Customer deposits			1,850
Total liabilities assumed			7,684
Total net assets acquired			99,759
Trade Name | Savvy Homes
Assets
Intangibles		407
Trade Name | Bonterra Builders, LLC
Assets
Intangibles			1,400
Non-compete intangible asset | Bonterra Builders, LLC
Assets
Intangibles			600
Earn-out | Savvy Homes
Business Acquisitions
Contingent consideration (earn-out)	$ 0	$ 1,818
Earn-out | Bonterra Builders, LLC
Business Acquisitions
Contingent consideration (earn-out)			$ 6,000