Segment Information, Nature of Operations, and Certain Concentrations - Interest Income (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Segment Reporting, Other Significant Reconciling Item [Line Items]
Consolidated interest income	$ 158,774	$ 44,311	$ 11,879
Mortgage Banking
Segment Reporting, Other Significant Reconciling Item [Line Items]
Interest income	16,687	11,853	8,725
Profit before taxes:
Segment Reporting, Other Significant Reconciling Item [Line Items]
Interest income	16,687	11,853	8,725
Other unallocated interest income
Segment Reporting, Other Significant Reconciling Item [Line Items]
Other unallocated interest income	$ 142,087	$ 32,458	$ 3,154