Investments - Rollforward of credit loss allowance for fixed income securities (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Credit Losses on Fixed Income Securities [Roll Forward]
Beginning balance	$ (6)	$ (2)
Ending balance	(13)	(6)	$ (2)
Fixed income securities
Credit Losses on Fixed Income Securities [Roll Forward]
Beginning balance	(6)	(2)	0
Credit losses on securities for which credit losses not previously reported	(1)	(5)	(2)
Net increases related to credit losses previously reported	(6)	1	0
Reduction of allowance related to sales	0	0	0
Write-offs	0	0	0
Ending balance	(13)	(6)	(2)
Corporate
Credit Losses on Fixed Income Securities [Roll Forward]
Beginning balance	(6)	(1)
Ending balance	(11)	(6)	(1)
ABS
Credit Losses on Fixed Income Securities [Roll Forward]
Beginning balance	0	(1)
Ending balance	$ (2)	$ 0	$ (1)