Segment Disclosures - Assets (Detail) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	$ 5,854,436	$ 5,777,141
Finance Lease, Right-of-Use Asset	14,973	15,772
Contract land deposit reserve	(38,831)	(52,205)
Home Building Segment
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	5,436,133	5,214,516
Cash and cash equivalents	2,597,565	2,714,720
Operating lease right-of-use assets	61,740	53,110
Mortgage Banking
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	418,303	562,625
Cash and cash equivalents	20,757	63,547
Operating lease right-of-use assets	11,627	12,439
Operating Segments
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	2,862,424	2,770,522
Operating Segments | Home Building Segment | Mid Atlantic
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	1,196,515	1,140,910
Operating Segments | Home Building Segment | North East
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	246,296	202,591
Operating Segments | Home Building Segment | Mid East
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	442,110	377,448
Operating Segments | Home Building Segment | South East
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	566,547	494,295
Operating Segments | Mortgage Banking
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	410,956	555,278
Corporate and Reconciling Items
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	2,992,012	3,006,619
Cash and cash equivalents	2,597,565	2,714,720
Deferred taxes	137,037	132,980
Intangible assets and goodwill	49,601	49,678
Operating lease right-of-use assets	61,740	53,110
Finance Lease, Right-of-Use Asset	14,973	15,772
Contract land deposit reserve	(38,831)	(52,205)
Consolidation adjustments and other	$ 169,927	$ 92,564