Segment Information, Nature of Operations, and Certain Concentrations - Profit before Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Equity-based compensation expense (1)	$ (78,532)	$ (75,701)	$ (44,562)
Corporate interest expense	(25,380)	(25,081)	(24,185)
Consolidated profit before taxes	1,025,795	959,732	846,911
Homebuilding:
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Corporate interest expense	(24,335)	(24,036)	(23,037)
Consolidated profit before taxes	923,879	871,106	776,370
Mortgage Banking:
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Corporate interest expense	(1,045)	(1,045)	(1,148)
Consolidated profit before taxes	101,916	88,626	70,541
Profit before taxes:
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Corporate interest expense	(225,627)	(215,016)	(199,586)
Consolidated profit before taxes	964,075	918,859	778,136
Profit before taxes: | Homebuilding: | Mid Atlantic
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Corporate interest expense	(123,178)	(123,908)	(123,075)
Consolidated profit before taxes	478,537	462,178	398,494
Profit before taxes: | Homebuilding: | North East
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Corporate interest expense	(19,804)	(17,897)	(16,117)
Consolidated profit before taxes	51,728	69,789	60,218
Profit before taxes: | Homebuilding: | Mid East
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Corporate interest expense	(37,266)	(35,804)	(29,663)
Consolidated profit before taxes	173,374	175,134	149,639
Profit before taxes: | Homebuilding: | South East
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Corporate interest expense	(44,334)	(36,362)	(29,583)
Consolidated profit before taxes	155,144	118,296	95,826
Profit before taxes: | Mortgage Banking:
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Corporate interest expense	(1,045)	(1,045)	(1,148)
Consolidated profit before taxes	105,292	93,462	73,959
Reconciling items:
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Equity-based compensation expense (1)	(78,532)	(75,701)	(44,562)
Corporate capital allocation (2)	224,468	213,903	198,384
Unallocated corporate overhead	(105,125)	(89,973)	(89,514)
Consolidation adjustments and other	45,130	16,612	27,450
Corporate interest expense	(24,221)	(23,968)	(22,983)
Consolidated profit before taxes	$ 61,720	$ 40,873	$ 68,775