Segment Disclosures - Profit before Taxes (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Consolidated profit before taxes	$ 62,363	$ 49,707
Corporate Capital Allocation [Member]
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Segment reporting reconciling amount for operating profit	36,945	28,966
Homebuilding Mid Atlantic [Member] | Corporate Capital Allocation [Member]
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Segment reporting reconciling amount for operating profit	23,411	18,156
Homebuilding North East [Member] | Corporate Capital Allocation [Member]
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Segment reporting reconciling amount for operating profit	3,310	2,449
Homebuilding Mid East [Member] | Corporate Capital Allocation [Member]
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Segment reporting reconciling amount for operating profit	5,935	5,298
Homebuilding South East [Member] | Corporate Capital Allocation [Member]
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Segment reporting reconciling amount for operating profit	4,289	3,063
Mortgage Banking [Member]
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Consolidated profit before taxes	5,779	991
Operating Segments [Member]
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Consolidated profit before taxes	73,052	56,955
Operating Segments [Member] | Homebuilding Mid Atlantic [Member]
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Consolidated profit before taxes	44,566	41,012
Operating Segments [Member] | Homebuilding North East [Member]
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Consolidated profit before taxes	5,983	6,306
Operating Segments [Member] | Homebuilding Mid East [Member]
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Consolidated profit before taxes	7,063	(249)
Operating Segments [Member] | Homebuilding South East [Member]
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Consolidated profit before taxes	8,815	8,046
Operating Segments [Member] | Mortgage Banking [Member]
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Consolidated profit before taxes	6,625	1,840
Segment Reconciling Items [Member] | Contract Land Deposit Reserve Adjustment [Member]
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Segment reporting reconciling amount for operating profit	903	1,983
Segment Reconciling Items [Member] | Equity-Based Compensation Expense [Member]
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Segment reporting reconciling amount for operating profit	(13,399)	(10,703)
Segment Reconciling Items [Member] | Corporate Capital Allocation [Member]
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Segment reporting reconciling amount for operating profit	36,945	28,966
Segment Reconciling Items [Member] | Unallocated Corporate Overhead [Member]
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Segment reporting reconciling amount for operating profit	(29,984)	(25,960)
Segment Reconciling Items [Member] | Corporate Interest Expense [Member]
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Segment reporting reconciling amount for operating profit	(5,803)	(5,675)
Consolidation adjustments and other [Member]
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Consolidated profit before taxes	649	4,141
Reconciling Items Sub-Total [Member]
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Consolidated profit before taxes	$ (10,689)	$ (7,248)