Segment Information, Nature of Operations, and Certain Concentrations - Expenditures for Property and Equipment (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Segment Reporting, Other Significant Reconciling Item [Line Items]
Expenditures for property and equipment:	$ 18,428	$ 17,875	$ 16,119
Profit before taxes:
Segment Reporting, Other Significant Reconciling Item [Line Items]
Expenditures for property and equipment:	18,012	17,491	15,919
Profit before taxes: | Home Building | Mid Atlantic
Segment Reporting, Other Significant Reconciling Item [Line Items]
Expenditures for property and equipment:	7,033	7,073	5,712
Profit before taxes: | Home Building | North East
Segment Reporting, Other Significant Reconciling Item [Line Items]
Expenditures for property and equipment:	1,420	1,062	1,083
Profit before taxes: | Home Building | Mid East
Segment Reporting, Other Significant Reconciling Item [Line Items]
Expenditures for property and equipment:	4,504	4,813	5,041
Profit before taxes: | Home Building | South East
Segment Reporting, Other Significant Reconciling Item [Line Items]
Expenditures for property and equipment:	3,993	4,142	3,818
Profit before taxes: | Mortgage Banking
Segment Reporting, Other Significant Reconciling Item [Line Items]
Expenditures for property and equipment:	1,062	401	265
Other unallocated interest income
Segment Reporting, Other Significant Reconciling Item [Line Items]
Expenditures for property and equipment:	$ 416	$ 384	$ 200