Business Acquisition - Purchase Price Consideration and Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands		6 Months Ended
	Jan. 08, 2018	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Business Acquisitions
Contingent consideration (earn-out)		$ 2,418	$ 1,818
Assets
Goodwill		$ 39,023		$ 30,290
Oakdale-Hampton Homes
Business Acquisitions
Cash payments to acquire businesses	$ 42,423
Total consideration	44,841
Assets
Receivables and other assets	719
Land and other inventories	34,933
Property, plant and equipment	798
Goodwill	8,733
Total assets acquired	45,743
Liabilities
Accounts payable	749
Accrued and other liabilities	84
Customer deposits	69
Total liabilities assumed	902
Total net assets acquired	44,841
Trade Name | Oakdale-Hampton Homes
Assets
Intangibles	560
Earn-out | Oakdale-Hampton Homes
Business Acquisitions
Contingent consideration (earn-out)	$ 2,418