Segment Information - Additional Information (Details) $ in Millions	3 Months Ended			9 Months Ended		12 Months Ended
	Sep. 30, 2024 USD ($)	Dec. 31, 2023	Sep. 30, 2023 USD ($)	Sep. 30, 2024 USD ($) Segment	Sep. 30, 2023 USD ($)	Dec. 31, 2023 Segment
Segment Reporting Information [Line Items]
Number of reportable segments | Segment				3		4
Revenues | $	$ 1,186		$ 1,068	$ 3,622	$ 3,231
Number of operating segments | Segment				3
Third-party Claims Administration and Adjusting Services Businesses | Services
Segment Reporting Information [Line Items]
Percentage of business sold		50.00%
England, Bermuda, Cayman, Islands and The Republic of Ireland
Segment Reporting Information [Line Items]
Revenues | $	$ 155		$ 127	$ 486	$ 374