Segment Information - Additional Information (Details) $ in Millions	3 Months Ended			12 Months Ended
	Mar. 31, 2024 USD ($) Segment	Dec. 31, 2023	Mar. 31, 2023 USD ($)	Dec. 31, 2023 Segment
Segment Reporting Information [Line Items]
Number of reportable segments | Segment	3			4
Number of operating segments | Segment	3
Revenues | $	$ 1,258		$ 1,116
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 | $	$ 159		$ 117