Segment Disclosures - Assets (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	$ 2,846,065	$ 2,989,279
Contract land deposit reserve	(27,871)	(29,999)
Homebuilding [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	2,451,422	2,584,880
Cash and cash equivalents	414,763	645,087
Mortgage Banking [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	394,643	404,399
Cash and cash equivalents	10,803	21,707
Operating Segments [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	2,236,539	2,160,009
Operating Segments [Member] | Homebuilding [Member] | Mid Atlantic [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	1,119,218	1,079,225
Operating Segments [Member] | Homebuilding [Member] | North East [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	152,835	143,008
Operating Segments [Member] | Homebuilding [Member] | Mid East [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	288,846	263,019
Operating Segments [Member] | Homebuilding [Member] | South East [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	288,344	277,705
Operating Segments [Member] | Mortgage Banking [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	387,296	397,052
Corporate and Reconciling Items [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	609,526	829,270
Cash and cash equivalents	414,763	645,087
Deferred taxes	113,462	111,953
Intangible assets and goodwill	50,105	50,144
Contract land deposit reserve	(27,871)	(29,999)
Consolidation adjustments and other	$ 59,067	$ 52,085