Goodwill (Carrying Amount of Goodwill by Reportable Segment) (Detail) $ in Millions	3 Months Ended
	Mar. 31, 2025 USD ($)
Goodwill [Line Items]
Balance at beginning of period	$ 1,804.3
Acquisitions	4.5
Foreign currency translation	0.8
Balance at end of period	1,809.6
Title Insurance and Services
Goodwill [Line Items]
Balance at beginning of period	1,763.4
Acquisitions	4.5
Foreign currency translation	0.8
Balance at end of period	1,768.7
Home Warranty
Goodwill [Line Items]
Balance at beginning of period	40.9
Acquisitions	0.0
Foreign currency translation	0.0
Balance at end of period	$ 40.9