Segment Information - Additional Information (Details) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2024 USD ($) Segment	Dec. 31, 2023 USD ($) Segment	Dec. 31, 2022 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | Segment		3	4
Revenues | $		$ 4,805	$ 4,257	$ 3,573
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 | $		$ 665	$ 527	$ 240