Investments - Rollforward of credit loss allowance for fixed income securities (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Fixed income securities
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Beginning balance	$ (6)	$ (1)	$ (6)	$ (3)
Net (increases) decreases related to credit losses previously reported	(4)	(1)	(4)	1
Reduction of allowance related to sales	0	0	0	0
Write-offs	0	0	0	0
Ending balance	(10)	(2)	(10)	(2)
Fixed income securities	10	2	10	2
Corporate
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Ending balance	(10)		(10)
Fixed income securities	$ 10		$ 10
ABS
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Ending balance		(1)		(1)
Fixed income securities		$ 1		$ 1