Segment Information, Nature of Operations, and Certain Concentrations - Corporate Capital Allocation Charge (Detail) - Reconciling Items [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Segment Reporting Other Significant Reconciling Item [Line Items]
Corporate capital allocation charge	$ 171,170	$ 152,140	$ 116,458
Homebuilding [Member] | Mid Atlantic [Member]
Segment Reporting Other Significant Reconciling Item [Line Items]
Corporate capital allocation charge	107,705	96,328	72,272
Homebuilding [Member] | North East [Member]
Segment Reporting Other Significant Reconciling Item [Line Items]
Corporate capital allocation charge	16,987	12,107	9,461
Homebuilding [Member] | Mid East [Member]
Segment Reporting Other Significant Reconciling Item [Line Items]
Corporate capital allocation charge	27,263	26,299	22,580
Homebuilding [Member] | South East [Member]
Segment Reporting Other Significant Reconciling Item [Line Items]
Corporate capital allocation charge	$ 19,215	$ 17,406	$ 12,145