Segment Disclosures - Corporate Capital Allocation Charge (Detail) - Corporate and Reconciling Items - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Segment Reporting, Other Significant Reconciling Item [Line Items]
Corporate capital allocation charge	$ 63,032	$ 59,870	$ 124,583	$ 116,521
Home Building Segment | Mid Atlantic
Segment Reporting, Other Significant Reconciling Item [Line Items]
Corporate capital allocation charge	31,135	31,581	61,731	61,336
Home Building Segment | North East
Segment Reporting, Other Significant Reconciling Item [Line Items]
Corporate capital allocation charge	6,457	5,790	12,495	11,349
Home Building Segment | Mid East
Segment Reporting, Other Significant Reconciling Item [Line Items]
Corporate capital allocation charge	11,066	9,687	21,690	19,050
Home Building Segment | South East
Segment Reporting, Other Significant Reconciling Item [Line Items]
Corporate capital allocation charge	$ 14,374	$ 12,812	$ 28,667	$ 24,786