Basis of Presentation (Narrative) (Details) $ / shares in Units, shares in Thousands, $ in Thousands		3 Months Ended	9 Months Ended
	Aug. 04, 2017 USD ($) $ / shares shares	Sep. 30, 2017 USD ($)	Sep. 30, 2017 USD ($) segment
Summary of Significant Accounting Policies [Line Items]
Number of operating segments | segment			4
Mortgage loans available-for-sale		$ 30,071	$ 30,071
Mortgage loans available-for-sale outstanding principal balance		28,700	28,700
Net gain from changes in fair value of mortgage loans held in inventory		800	1,400
Realized net gains from the sale of mortgages		$ 500	600
ASU 2016-09 [Member]
Summary of Significant Accounting Policies [Line Items]
Excess tax benefit			$ 1,100
UCP, Inc [Member]
Summary of Significant Accounting Policies [Line Items]
Business acquisition, paid in cash	$ 96,213
Common stock, price per share | $ / shares	$ 25.80
Common Class A [Member] | UCP, Inc [Member]
Summary of Significant Accounting Policies [Line Items]
Conversion of stock, cash | $ / shares	$ 5.32
Century Common Stock [Member] | UCP, Inc [Member]
Summary of Significant Accounting Policies [Line Items]
Conversion of stock, ratio	0.2309%
Shares issued in connection to merger | shares	4,176