Segment Disclosures - Corporate Capital Allocation Charge (Detail) - Reconciling Items [Member] - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Segment Reporting Other Significant Reconciling Item [Line Items]
Corporate capital allocation charge	$ 46,259	$ 41,398	$ 90,574	$ 78,341
Homebuilding [Member] | Mid Atlantic [Member]
Segment Reporting Other Significant Reconciling Item [Line Items]
Corporate capital allocation charge	28,766	26,258	55,951	49,667
Homebuilding [Member] | North East [Member]
Segment Reporting Other Significant Reconciling Item [Line Items]
Corporate capital allocation charge	4,447	3,805	9,400	7,115
Homebuilding [Member] | Mid East [Member]
Segment Reporting Other Significant Reconciling Item [Line Items]
Corporate capital allocation charge	7,458	6,672	14,157	12,607
Homebuilding [Member] | South East [Member]
Segment Reporting Other Significant Reconciling Item [Line Items]
Corporate capital allocation charge	$ 5,588	$ 4,663	$ 11,066	$ 8,952