Investments - OTTI losses by asset type (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Realized capital gains and losses by asset type
Fixed income securities	$ 12	$ 1	$ 14	$ (36)
Total credit losses by asset type	12	0	14	(36)
Commitments to fund commercial mortgage loans, bank loans and agent loans	0	1	0	0
Fixed income securities
Realized capital gains and losses by asset type
Fixed income securities	(1)	(1)	1	(3)
Corporate
Realized capital gains and losses by asset type
Fixed income securities	(1)	0	0	(1)
ABS
Realized capital gains and losses by asset type
Fixed income securities	0	(2)	1	(2)
MBS
Realized capital gains and losses by asset type
Fixed income securities	0	1	0	0
Mortgage loans
Realized capital gains and losses by asset type
Total credit losses by asset type	11	6	17	(3)
Limited partnership interests
Realized capital gains and losses by asset type
Total credit losses by asset type	0	(1)	0	(6)
Bank loans, net
Realized capital gains and losses by asset type
Total credit losses by asset type	3	(4)	(3)	(24)
Agent loans, net
Realized capital gains and losses by asset type
Total credit losses by asset type	$ (1)	$ 0	$ (1)	$ 0