Investments - Allowance for credit losses on fixed maturities (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Jan. 01, 2020
Allowance for Credit Losses [Roll Forward]
Beginning balance	$ 12	$ 0
Impact of adoption of new accounting policy	9	12
Initial allowance for purchased securities with credit deterioration	0	0
Provision for expected credit losses on securities with no previous allowance	1	16
Additions (reductions) to previously recognized expected credit losses	(2)	(3)
Reductions due to sales or redemptions	2	1
Ending balance	9	12
Structured securities
Allowance for Credit Losses [Roll Forward]
Beginning balance	10	0
Impact of adoption of new accounting policy	8	10
Initial allowance for purchased securities with credit deterioration	0	0
Provision for expected credit losses on securities with no previous allowance	0	11
Additions (reductions) to previously recognized expected credit losses	(2)	(1)
Reductions due to sales or redemptions	0	0
Ending balance	8	10
Corporate and other
Allowance for Credit Losses [Roll Forward]
Beginning balance	2	0
Impact of adoption of new accounting policy	1	2
Initial allowance for purchased securities with credit deterioration	0	0
Provision for expected credit losses on securities with no previous allowance	1	5
Additions (reductions) to previously recognized expected credit losses	0	(2)
Reductions due to sales or redemptions	2	1
Ending balance	$ 1	$ 2
Accounting Standards Update 2016-13
Allowance for Credit Losses [Roll Forward]
Impact of adoption of new accounting policy			$ 0
Accounting Standards Update 2016-13 | Structured securities
Allowance for Credit Losses [Roll Forward]
Impact of adoption of new accounting policy			0
Accounting Standards Update 2016-13 | Corporate and other
Allowance for Credit Losses [Roll Forward]
Impact of adoption of new accounting policy			$ 0