Segment Disclosures - Profit before Taxes (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Profit before taxes	$ 184,996	$ 143,791	$ 396,043	$ 302,322
Equity-based compensation expense			(39,874)	(44,874)
Interest charged to interest expense	(6,081)	(5,775)	(17,955)	(17,292)
Homebuilding [Member]
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Profit before taxes	168,874	136,511	362,706	287,805
Interest charged to interest expense	(5,900)	(5,618)	(17,499)	(16,895)
Mortgage Banking [Member]
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Profit before taxes	16,122	7,280	33,337	14,517
Interest charged to interest expense	(181)	(157)	(456)	(397)
Operating Segments [Member]
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Profit before taxes	163,099	122,682	374,290	281,820
Operating Segments [Member] | Homebuilding [Member] | Mid Atlantic [Member]
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Profit before taxes	88,058	76,542	217,665	184,900
Operating Segments [Member] | Homebuilding [Member] | North East [Member]
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Profit before taxes	10,745	9,056	29,359	23,761
Operating Segments [Member] | Homebuilding [Member] | Mid East [Member]
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Profit before taxes	29,958	18,374	52,607	29,241
Operating Segments [Member] | Homebuilding [Member] | South East [Member]
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Profit before taxes	17,372	10,093	38,812	26,034
Operating Segments [Member] | Mortgage Banking [Member]
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Profit before taxes	16,966	8,617	35,847	17,884
Reconciling Items [Member]
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Profit before taxes	21,897	21,109	21,753	20,502
Contract land deposit reserve adjustment	4,705	453	11,511	4,108
Equity-based compensation expense	(13,571)	(18,233)	(39,874)	(44,874)
Corporate capital allocation	45,690	42,220	124,033	105,697
Unallocated corporate overhead	(18,055)	(8,179)	(67,803)	(49,652)
Consolidation adjustments and other	9,147	10,464	11,477	22,093
Interest charged to interest expense	(6,019)	(5,616)	(17,591)	(16,870)
Reconciling Items [Member] | Homebuilding [Member] | Mid Atlantic [Member]
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Corporate capital allocation	28,743	27,187	78,412	67,085
Reconciling Items [Member] | Homebuilding [Member] | North East [Member]
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Corporate capital allocation	4,451	3,151	11,566	8,333
Reconciling Items [Member] | Homebuilding [Member] | Mid East [Member]
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Corporate capital allocation	7,472	7,202	20,079	18,680
Reconciling Items [Member] | Homebuilding [Member] | South East [Member]
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Corporate capital allocation	$ 5,024	$ 4,680	$ 13,976	$ 11,599