Reserve for Known and Incurred but Not Reported Claims (Narrative) (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Insurance [Abstract]
Provision for title loss, percentage of title premiums and escrow fees	3.00%	4.00%	3.33%	4.00%
Ultimate loss rate			3.75%
Estimated increase in loss reserve for prior policy years				$ 0.0
Percentage reserve releases for prior policy years	0.75%		0.42%
Reserve releases for prior policy years	$ 8.6		$ 14.0