Investments - Rollforward of credit loss allowance for fixed income securities (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Ending balance	$ (29)	$ (10)	$ (29)	$ (10)
Fixed income securities
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Beginning balance	(22)	(6)	(13)	(6)
Credit losses on securities for which credit losses not previously reported	(4)	0	(4)	0
Net increases related to credit losses previously reported	(3)	(4)	(12)	(4)
Reduction of allowance related to sales	0	0	0	0
Write-offs	0	0	0	0
Ending balance	(29)	(10)	(29)	(10)
Corporate
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Ending balance	(27)	(10)	(27)	(10)
ABS
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Ending balance	$ (2)	$ 0	$ (2)	$ 0