Segment Information, Nature of Operations, and Certain Concentrations - Revenues (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting, Revenue Reconciling Item [Line Items]
Consolidated revenues									$ 7,388,664	$ 7,163,674	$ 6,305,840
Homebuilding:
Segment Reporting, Revenue Reconciling Item [Line Items]
Consolidated revenues	$ 1,946,859	$ 1,873,331	$ 1,757,448	$ 1,643,206	$ 1,954,403	$ 1,809,345	$ 1,750,463	$ 1,490,093	7,220,844	7,004,304	6,175,521
Homebuilding: | Mid Atlantic
Segment Reporting, Revenue Reconciling Item [Line Items]
Consolidated revenues									3,901,573	3,893,358	3,543,687
Homebuilding: | North East
Segment Reporting, Revenue Reconciling Item [Line Items]
Consolidated revenues									514,804	580,726	517,141
Homebuilding: | Mid East
Segment Reporting, Revenue Reconciling Item [Line Items]
Consolidated revenues									1,501,139	1,455,834	1,250,165
Homebuilding: | South East
Segment Reporting, Revenue Reconciling Item [Line Items]
Consolidated revenues									1,303,328	1,074,386	864,528
Mortgage Banking:
Segment Reporting, Revenue Reconciling Item [Line Items]
Consolidated revenues	$ 43,336	$ 37,933	$ 42,746	$ 43,805	$ 40,145	$ 43,062	$ 36,842	$ 39,321	$ 167,820	$ 159,370	$ 130,319