Segment Disclosures - Profit before Taxes (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Profit before taxes	$ 132,161	$ 103,312
Equity-based compensation expense	(10,589)	(10,549)
Corporate interest expense	(5,836)	(5,088)
Homebuilding [Member]
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Profit before taxes	117,190	93,654
Corporate interest expense	(5,578)	(4,842)
Mortgage Banking [Member]
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Profit before taxes	14,971	9,658
Corporate interest expense	(258)	(246)
Operating Segments [Member]
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Profit before taxes	126,276	96,568
Operating Segments [Member] | Homebuilding [Member] | Mid Atlantic [Member]
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Profit before taxes	64,489	46,609
Operating Segments [Member] | Homebuilding [Member] | North East [Member]
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Profit before taxes	9,106	4,065
Operating Segments [Member] | Homebuilding [Member] | Mid East [Member]
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Profit before taxes	22,159	22,733
Operating Segments [Member] | Homebuilding [Member] | South East [Member]
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Profit before taxes	14,569	12,786
Operating Segments [Member] | Mortgage Banking [Member]
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Profit before taxes	15,953	10,375
Corporate and Reconciling Items [Member]
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Profit before taxes	5,885	6,744
Contract land deposit reserve adjustment	(728)	1,329
Equity-based compensation expense	(10,589)	(10,549)
Corporate capital allocation	46,187	44,315
Unallocated corporate overhead	(27,234)	(29,509)
Consolidation adjustments and other	3,813	5,985
Corporate interest expense	(5,564)	(4,827)
Corporate and Reconciling Items [Member] | Homebuilding [Member] | Mid Atlantic [Member]
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Corporate capital allocation	29,124	27,186
Corporate and Reconciling Items [Member] | Homebuilding [Member] | North East [Member]
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Corporate capital allocation	3,814	4,953
Corporate and Reconciling Items [Member] | Homebuilding [Member] | Mid East [Member]
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Corporate capital allocation	6,742	6,699
Corporate and Reconciling Items [Member] | Homebuilding [Member] | South East [Member]
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Corporate capital allocation	$ 6,507	$ 5,477