Segment Disclosures - Assets (Detail) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	$ 3,887,523	$ 3,809,815
Contract land deposit reserve	(63,188)	(27,572)
Home Building [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	3,357,646	3,242,061
Cash and cash equivalents	1,078,598	1,110,892
Operating lease right-of-use assets	60,003	63,825
Mortgage Banking [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	529,877	567,754
Cash and cash equivalents	13,398	29,412
Operating lease right-of-use assets	15,613	13,345
Operating Segments [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	2,579,259	2,447,015
Operating Segments [Member] | Home Building [Member] | Mid Atlantic [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	1,118,067	1,024,996
Operating Segments [Member] | Home Building [Member] | North East [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	190,991	166,860
Operating Segments [Member] | Home Building [Member] | Mid East [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	325,693	293,773
Operating Segments [Member] | Home Building [Member] | South East [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	421,978	400,979
Operating Segments [Member] | Mortgage Banking [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	522,530	560,407
Corporate and Reconciling Items [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	1,308,264	1,362,800
Cash and cash equivalents	1,078,598	1,110,892
Deferred taxes	117,868	115,731
Intangible assets and goodwill	49,795	49,834
Operating lease right-of-use assets	60,003	63,825
Contract land deposit reserve	(63,188)	(27,572)
Consolidation adjustments and other	$ 65,188	$ 50,090