Reinsurance and Indemnification - Schedule of Rollforward of Credit Loss Allowance for Reinsurance Recoverables (Details) - Property and casualty - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Reinsurance Recoverable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ (63)	$ (62)
Decrease (increase) in the provision for credit losses	0	(2)
Write-offs	0	0
Ending balance	$ (63)	$ (64)