Business Combinations (Narrative) (Details) $ / shares in Units, shares in Thousands			3 Months Ended
	Aug. 17, 2017 USD ($)	Aug. 04, 2017 USD ($) item $ / shares shares	Mar. 31, 2018 USD ($)	Mar. 31, 2017 USD ($)	Oct. 31, 2017 USD ($)
Business Combinations [Line Items]
Acquisition expense			$ 173,000	$ 523,000
Income before tax expense			23,107,000	$ 12,051,000
UCP, Inc [Member]
Business Combinations [Line Items]
Cash paid per share | $ / shares		$ 5.32
Conversion of stock, ratio		0.2309%
Total cash consideration		$ 100,150.0000
Cash acquired from business acquisition		$ 20,264,000
Fractional shares | shares		0
Total fair value of awards		$ 6,200,000
Total fair value of award attribute to services performed by UCP		1,149,000
Expense related to refinements of estimated fair value of inventories			1,500,000
Acquisition expense		9,600,000
Total consideration in cash and equity		$ 209,036,000
Number of lots | item		4,199
Number of communities | item		43
Number of homes in backlog | item		346
Number of model homes | item		59
Proceeds from sale of BMCH South Carolina, LLC operations	$ 17,100,000
Goodwill amount expected to be tax deductible			6,500,000
Homebuilding revenues			103,400,000
Income before tax expense			$ 6,600,000
UCP, Inc [Member] | Minimum [Member]
Business Combinations [Line Items]
Market gross margin			6.00%
UCP, Inc [Member] | Maximum [Member]
Business Combinations [Line Items]
Market gross margin			20.00%
UCP, Inc [Member] | Restricted Stock Units [Member]
Business Combinations [Line Items]
Conversion of stock, shares | shares		200
Sundquist [Member]
Business Combinations [Line Items]
Total consideration in cash and equity					$ 50,203,000
Goodwill amount expected to be tax deductible			$ 4,800,000
Homebuilding revenues			21,400,000
Income before tax expense			$ 4,100,000
Sundquist [Member] | Minimum [Member]
Business Combinations [Line Items]
Market gross margin			6.00%
Sundquist [Member] | Maximum [Member]
Business Combinations [Line Items]
Market gross margin			20.00%
Century Common Stock [Member] | UCP, Inc [Member]
Business Combinations [Line Items]
Shares issued in connection to merger | shares		4,176