Segment Disclosures - Corporate Capital Allocation Charge (Detail) - Reconciling Items [Member] - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Segment Reporting Other Significant Reconciling Item [Line Items]
Corporate capital allocation charge	$ 41,398	$ 34,511	$ 78,341	$ 63,477
Homebuilding Mid Atlantic [Member]
Segment Reporting Other Significant Reconciling Item [Line Items]
Corporate capital allocation charge	26,258	21,742	49,667	39,898
Homebuilding North East [Member]
Segment Reporting Other Significant Reconciling Item [Line Items]
Corporate capital allocation charge	3,805	2,733	7,115	5,182
Homebuilding Mid East [Member]
Segment Reporting Other Significant Reconciling Item [Line Items]
Corporate capital allocation charge	6,672	6,180	12,607	11,478
Homebuilding South East [Member]
Segment Reporting Other Significant Reconciling Item [Line Items]
Corporate capital allocation charge	$ 4,663	$ 3,856	$ 8,952	$ 6,919