Segment Disclosures - Revenues (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	$ 1,911,264	$ 1,852,407	$ 5,398,469	$ 5,169,126
Home Building [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	1,873,331	1,809,345	5,273,985	5,049,901
Home Building [Member] | Mid Atlantic [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	1,012,056	991,077	2,875,411	2,807,251
Home Building [Member] | North East [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	120,478	152,858	364,909	423,190
Home Building [Member] | Mid East [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	406,145	391,933	1,104,603	1,045,458
Home Building [Member] | South East [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	334,652	273,477	929,062	774,002
Mortgage Banking [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	$ 37,933	$ 43,062	$ 124,484	$ 119,225