Segment Information, Nature of Operations, and Certain Concentrations - Expenditures for Property and Equipment (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Segment Reporting, Other Significant Reconciling Item [Line Items]
Expenditures for property and equipment:	$ 17,875	$ 16,119	$ 22,699
Profit before taxes:
Segment Reporting, Other Significant Reconciling Item [Line Items]
Expenditures for property and equipment:	17,491	15,919	21,282
Profit before taxes: | Home Building | Mid Atlantic
Segment Reporting, Other Significant Reconciling Item [Line Items]
Expenditures for property and equipment:	7,073	5,712	9,218
Profit before taxes: | Home Building | North East
Segment Reporting, Other Significant Reconciling Item [Line Items]
Expenditures for property and equipment:	1,062	1,083	2,000
Profit before taxes: | Home Building | Mid East
Segment Reporting, Other Significant Reconciling Item [Line Items]
Expenditures for property and equipment:	4,813	5,041	5,221
Profit before taxes: | Home Building | South East
Segment Reporting, Other Significant Reconciling Item [Line Items]
Expenditures for property and equipment:	4,142	3,818	3,944
Profit before taxes: | Mortgage Banking
Segment Reporting, Other Significant Reconciling Item [Line Items]
Expenditures for property and equipment:	401	265	899
Other unallocated interest income
Segment Reporting, Other Significant Reconciling Item [Line Items]
Expenditures for property and equipment:	$ 384	$ 200	$ 1,417