Segment Disclosures - Corporate Capital Allocation Charge (Detail) - Corporate and Reconciling Items [Member] - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Segment Reporting, Other Significant Reconciling Item [Line Items]
Corporate capital allocation charge	$ 56,650	$ 54,559
Home Building [Member] | Mid Atlantic [Member]
Segment Reporting, Other Significant Reconciling Item [Line Items]
Corporate capital allocation charge	29,755	30,417
Home Building [Member] | North East [Member]
Segment Reporting, Other Significant Reconciling Item [Line Items]
Corporate capital allocation charge	5,558	4,727
Home Building [Member] | Mid East [Member]
Segment Reporting, Other Significant Reconciling Item [Line Items]
Corporate capital allocation charge	9,363	9,015
Home Building [Member] | South East [Member]
Segment Reporting, Other Significant Reconciling Item [Line Items]
Corporate capital allocation charge	$ 11,974	$ 10,400