Segment Information, Nature of Operations, and Certain Concentrations - Interest Expense (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Segment Reporting Other Significant Reconciling Item [Line Items]
Consolidated interest expense	$ 21,707	$ 23,559	$ 23,140
Homebuilding [Member]
Segment Reporting Other Significant Reconciling Item [Line Items]
Consolidated interest expense	20,621	22,918	22,591
Mortgage Banking [Member]
Segment Reporting Other Significant Reconciling Item [Line Items]
Consolidated interest expense	1,086	641	549
Operating Segments [Member]
Segment Reporting Other Significant Reconciling Item [Line Items]
Consolidated interest expense	191,146	171,860	152,736
Operating Segments [Member] | Homebuilding [Member] | Mid Atlantic [Member]
Segment Reporting Other Significant Reconciling Item [Line Items]
Consolidated interest expense	119,808	107,748	96,364
Operating Segments [Member] | Homebuilding [Member] | North East [Member]
Segment Reporting Other Significant Reconciling Item [Line Items]
Consolidated interest expense	18,141	16,991	12,114
Operating Segments [Member] | Homebuilding [Member] | Mid East [Member]
Segment Reporting Other Significant Reconciling Item [Line Items]
Consolidated interest expense	28,307	27,263	26,300
Operating Segments [Member] | Homebuilding [Member] | South East [Member]
Segment Reporting Other Significant Reconciling Item [Line Items]
Consolidated interest expense	23,804	19,217	17,409
Operating Segments [Member] | Mortgage Banking [Member]
Segment Reporting Other Significant Reconciling Item [Line Items]
Consolidated interest expense	1,086	641	549
Reconciling Items [Member]
Segment Reporting Other Significant Reconciling Item [Line Items]
Consolidated interest expense	20,553	22,869	22,544
Corporate capital allocation	(189,992)	(171,170)	(152,140)
Reconciling Items [Member] | Homebuilding [Member] | Mid Atlantic [Member]
Segment Reporting Other Significant Reconciling Item [Line Items]
Corporate capital allocation	(119,758)	(107,705)	(96,328)
Reconciling Items [Member] | Homebuilding [Member] | North East [Member]
Segment Reporting Other Significant Reconciling Item [Line Items]
Corporate capital allocation	(18,132)	(16,987)	(12,107)
Reconciling Items [Member] | Homebuilding [Member] | Mid East [Member]
Segment Reporting Other Significant Reconciling Item [Line Items]
Corporate capital allocation	(28,303)	(27,263)	(26,299)
Reconciling Items [Member] | Homebuilding [Member] | South East [Member]
Segment Reporting Other Significant Reconciling Item [Line Items]
Corporate capital allocation	$ (23,799)	$ (19,215)	$ (17,406)