Investments - Rollforward of credit loss allowance for fixed income securities (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Fixed income securities
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Beginning balance	$ (10)	$ (2)	$ (6)	$ (3)
Credit losses on securities for which credit losses not previously reported	(2)	0	(2)	0
Net (increases) decreases related to credit losses previously reported	(2)	0	(6)	1
Reduction of allowance related to sales	1	0	1	0
Write-offs	0	0	0	0
Ending balance	(13)	(2)	(13)	(2)
Fixed income securities	13	2	13	2
Corporate
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Ending balance	(11)	(1)	(11)	(1)
Fixed income securities	11	1	11	1
ABS
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Ending balance	(2)	(1)	(2)	(1)
Fixed income securities	$ 2	$ 1	$ 2	$ 1