Segment Information, Nature of Operations, and Certain Concentrations - Revenues (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Segment Reporting Revenue Reconciling Item [Line Items]
Consolidated revenues									$ 5,822,544	$ 5,159,008	$ 4,444,568
Homebuilding [Member]
Segment Reporting Revenue Reconciling Item [Line Items]
Revenues	$ 1,718,527	$ 1,507,451	$ 1,361,741	$ 1,121,504	$ 1,528,084	$ 1,374,467	$ 1,221,111	$ 941,538	5,709,223	5,065,200	4,375,059
Homebuilding [Member] | Mid Atlantic [Member]
Segment Reporting Revenue Reconciling Item [Line Items]
Revenues									3,319,776	3,022,789	2,617,108
Homebuilding [Member] | North East [Member]
Segment Reporting Revenue Reconciling Item [Line Items]
Revenues									462,385	432,145	376,862
Homebuilding [Member] | Mid East [Member]
Segment Reporting Revenue Reconciling Item [Line Items]
Revenues									1,192,472	1,014,920	892,513
Homebuilding [Member] | South East [Member]
Segment Reporting Revenue Reconciling Item [Line Items]
Revenues									734,590	595,346	488,576
Mortgage Banking [Member]
Segment Reporting Revenue Reconciling Item [Line Items]
Mortgage Banking	$ 34,239	$ 30,118	$ 26,442	$ 22,522	$ 27,191	$ 27,884	$ 22,522	$ 16,211	$ 113,321	$ 93,808	$ 69,509