Segment Information, Nature of Operations, and Certain Concentrations - Interest Expense (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting, Other Significant Reconciling Item [Line Items]
Consolidated interest expense	$ 25,081	$ 24,185	$ 21,707
Homebuilding:
Segment Reporting, Other Significant Reconciling Item [Line Items]
Consolidated interest expense	24,036	23,037	20,621
Mortgage Banking:
Segment Reporting, Other Significant Reconciling Item [Line Items]
Consolidated interest expense	1,045	1,148	1,086
Profit before taxes:
Segment Reporting, Other Significant Reconciling Item [Line Items]
Consolidated interest expense	215,016	199,586	191,146
Profit before taxes: | Homebuilding: | Mid Atlantic
Segment Reporting, Other Significant Reconciling Item [Line Items]
Consolidated interest expense	123,908	123,075	119,808
Profit before taxes: | Homebuilding: | North East
Segment Reporting, Other Significant Reconciling Item [Line Items]
Consolidated interest expense	17,897	16,117	18,141
Profit before taxes: | Homebuilding: | Mid East
Segment Reporting, Other Significant Reconciling Item [Line Items]
Consolidated interest expense	35,804	29,663	28,307
Profit before taxes: | Homebuilding: | South East
Segment Reporting, Other Significant Reconciling Item [Line Items]
Consolidated interest expense	36,362	29,583	23,804
Profit before taxes: | Mortgage Banking:
Segment Reporting, Other Significant Reconciling Item [Line Items]
Consolidated interest expense	1,045	1,148	1,086
Reconciling items:
Segment Reporting, Other Significant Reconciling Item [Line Items]
Consolidated interest expense	23,968	22,983	20,553
Corporate capital allocation charge	$ 213,903	$ 198,384	$ 189,992