Segment Information (Narrative) (Detail) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021 USD ($)	Sep. 30, 2020 USD ($)	Sep. 30, 2021 USD ($) State	Sep. 30, 2020 USD ($)
Segment Reporting Information [Line Items]
Number of states issues title insurance policies			49
Number of states licensed to issues property and casualty insurance policies			50
Number of states issues home warranty contracts			35
Net realized investment gains | $	$ 275,243	$ 44,992	$ 428,590	$ 49,491
Corporate
Segment Reporting Information [Line Items]
Net realized investment gains | $	$ 85,800