Policyholders' account balances (Guaranteed Minimum Crediting Rates) (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	$ 7,462	$ 3,140	$ 2,766
Universal Life
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	1,876	1,199	875
Universal Life | Policyholder Account Balance, at Guaranteed Minimum Crediting Rate
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	579	553	268
Universal Life | Policyholder Account Balance, above Guaranteed Minimum Crediting Rate, Range from 0001 to 0050
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	319	343	386
Universal Life | Policyholder Account Balance, above Guaranteed Minimum Crediting Rate, Range from 0051 to 0150
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	923	298	217
Universal Life | Policyholder Account Balance, above Guaranteed Minimum Crediting Rate, Range from 0151 and Greater
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	55	5	4
Annuities [Member]
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	2,411
Annuities [Member] | Policyholder Account Balance, at Guaranteed Minimum Crediting Rate
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	832
Annuities [Member] | Policyholder Account Balance, above Guaranteed Minimum Crediting Rate, Range from 0001 to 0050
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	0
Annuities [Member] | Policyholder Account Balance, above Guaranteed Minimum Crediting Rate, Range from 0051 to 0150
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	1,579
Annuities [Member] | Policyholder Account Balance, above Guaranteed Minimum Crediting Rate, Range from 0151 and Greater
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	0
Insurance, Other [Member]
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	2,502	1,374	1,388
Insurance, Other [Member] | Policyholder Account Balance, at Guaranteed Minimum Crediting Rate
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	1,160	920	701
Insurance, Other [Member] | Policyholder Account Balance, above Guaranteed Minimum Crediting Rate, Range from 0001 to 0050
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	540	41	201
Insurance, Other [Member] | Policyholder Account Balance, above Guaranteed Minimum Crediting Rate, Range from 0051 to 0150
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	256	217	266
Insurance, Other [Member] | Policyholder Account Balance, above Guaranteed Minimum Crediting Rate, Range from 0151 and Greater
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	546	196	220
Policyholder account balance, guaranteed minimum credit rating, range from 0000 to 0200 | Universal Life
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	540	493	212
Policyholder account balance, guaranteed minimum credit rating, range from 0000 to 0200 | Universal Life | Policyholder Account Balance, at Guaranteed Minimum Crediting Rate
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	475	451	166
Policyholder account balance, guaranteed minimum credit rating, range from 0000 to 0200 | Universal Life | Policyholder Account Balance, above Guaranteed Minimum Crediting Rate, Range from 0001 to 0050
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	0	0	0
Policyholder account balance, guaranteed minimum credit rating, range from 0000 to 0200 | Universal Life | Policyholder Account Balance, above Guaranteed Minimum Crediting Rate, Range from 0051 to 0150
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	29	37	42
Policyholder account balance, guaranteed minimum credit rating, range from 0000 to 0200 | Universal Life | Policyholder Account Balance, above Guaranteed Minimum Crediting Rate, Range from 0151 and Greater
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	36	5	4
Policyholder account balance, guaranteed minimum credit rating, range from 0000 to 0200 | Annuities [Member]
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	2,302
Policyholder account balance, guaranteed minimum credit rating, range from 0000 to 0200 | Annuities [Member] | Policyholder Account Balance, at Guaranteed Minimum Crediting Rate
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	723
Policyholder account balance, guaranteed minimum credit rating, range from 0000 to 0200 | Annuities [Member] | Policyholder Account Balance, above Guaranteed Minimum Crediting Rate, Range from 0001 to 0050
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	0
Policyholder account balance, guaranteed minimum credit rating, range from 0000 to 0200 | Annuities [Member] | Policyholder Account Balance, above Guaranteed Minimum Crediting Rate, Range from 0051 to 0150
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	1,579
Policyholder account balance, guaranteed minimum credit rating, range from 0000 to 0200 | Annuities [Member] | Policyholder Account Balance, above Guaranteed Minimum Crediting Rate, Range from 0151 and Greater
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	0
Policyholder account balance, guaranteed minimum credit rating, range from 0000 to 0200 | Insurance, Other [Member]
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	1,556	947	979
Policyholder account balance, guaranteed minimum credit rating, range from 0000 to 0200 | Insurance, Other [Member] | Policyholder Account Balance, at Guaranteed Minimum Crediting Rate
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	782	534	525
Policyholder account balance, guaranteed minimum credit rating, range from 0000 to 0200 | Insurance, Other [Member] | Policyholder Account Balance, above Guaranteed Minimum Crediting Rate, Range from 0001 to 0050
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	0	0	0
Policyholder account balance, guaranteed minimum credit rating, range from 0000 to 0200 | Insurance, Other [Member] | Policyholder Account Balance, above Guaranteed Minimum Crediting Rate, Range from 0051 to 0150
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	228	217	234
Policyholder account balance, guaranteed minimum credit rating, range from 0000 to 0200 | Insurance, Other [Member] | Policyholder Account Balance, above Guaranteed Minimum Crediting Rate, Range from 0151 and Greater
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	546	196	220
Policyholder account balance, guaranteed minimum credit rating, range from 0201 to 0400 | Universal Life
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	1,314	681	627
Policyholder account balance, guaranteed minimum credit rating, range from 0201 to 0400 | Universal Life | Policyholder Account Balance, at Guaranteed Minimum Crediting Rate
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	82	77	66
Policyholder account balance, guaranteed minimum credit rating, range from 0201 to 0400 | Universal Life | Policyholder Account Balance, above Guaranteed Minimum Crediting Rate, Range from 0001 to 0050
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	319	343	386
Policyholder account balance, guaranteed minimum credit rating, range from 0201 to 0400 | Universal Life | Policyholder Account Balance, above Guaranteed Minimum Crediting Rate, Range from 0051 to 0150
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	894	261	175
Policyholder account balance, guaranteed minimum credit rating, range from 0201 to 0400 | Universal Life | Policyholder Account Balance, above Guaranteed Minimum Crediting Rate, Range from 0151 and Greater
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	19	0	0
Policyholder account balance, guaranteed minimum credit rating, range from 0201 to 0400 | Annuities [Member]
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	109
Policyholder account balance, guaranteed minimum credit rating, range from 0201 to 0400 | Annuities [Member] | Policyholder Account Balance, at Guaranteed Minimum Crediting Rate
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	109
Policyholder account balance, guaranteed minimum credit rating, range from 0201 to 0400 | Annuities [Member] | Policyholder Account Balance, above Guaranteed Minimum Crediting Rate, Range from 0001 to 0050
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	0
Policyholder account balance, guaranteed minimum credit rating, range from 0201 to 0400 | Annuities [Member] | Policyholder Account Balance, above Guaranteed Minimum Crediting Rate, Range from 0051 to 0150
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	0
Policyholder account balance, guaranteed minimum credit rating, range from 0201 to 0400 | Annuities [Member] | Policyholder Account Balance, above Guaranteed Minimum Crediting Rate, Range from 0151 and Greater
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	0
Policyholder account balance, guaranteed minimum credit rating, range from 0201 to 0400 | Insurance, Other [Member]
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	941	423	404
Policyholder account balance, guaranteed minimum credit rating, range from 0201 to 0400 | Insurance, Other [Member] | Policyholder Account Balance, at Guaranteed Minimum Crediting Rate
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	373	382	171
Policyholder account balance, guaranteed minimum credit rating, range from 0201 to 0400 | Insurance, Other [Member] | Policyholder Account Balance, above Guaranteed Minimum Crediting Rate, Range from 0001 to 0050
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	540	41	201
Policyholder account balance, guaranteed minimum credit rating, range from 0201 to 0400 | Insurance, Other [Member] | Policyholder Account Balance, above Guaranteed Minimum Crediting Rate, Range from 0051 to 0150
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	28	0	32
Policyholder account balance, guaranteed minimum credit rating, range from 0201 to 0400 | Insurance, Other [Member] | Policyholder Account Balance, above Guaranteed Minimum Crediting Rate, Range from 0151 and Greater
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	0	0	0
Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range from 0400 and Greater | Universal Life
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	22	25	36
Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range from 0400 and Greater | Universal Life | Policyholder Account Balance, at Guaranteed Minimum Crediting Rate
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	22	25	36
Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range from 0400 and Greater | Universal Life | Policyholder Account Balance, above Guaranteed Minimum Crediting Rate, Range from 0001 to 0050
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	0	0	0
Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range from 0400 and Greater | Universal Life | Policyholder Account Balance, above Guaranteed Minimum Crediting Rate, Range from 0051 to 0150
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	0	0	0
Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range from 0400 and Greater | Universal Life | Policyholder Account Balance, above Guaranteed Minimum Crediting Rate, Range from 0151 and Greater
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	0	0	0
Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range from 0400 and Greater | Insurance, Other [Member]
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	5	4	5
Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range from 0400 and Greater | Insurance, Other [Member] | Policyholder Account Balance, at Guaranteed Minimum Crediting Rate
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	5	4	5
Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range from 0400 and Greater | Insurance, Other [Member] | Policyholder Account Balance, above Guaranteed Minimum Crediting Rate, Range from 0001 to 0050
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	0	0	0
Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range from 0400 and Greater | Insurance, Other [Member] | Policyholder Account Balance, above Guaranteed Minimum Crediting Rate, Range from 0051 to 0150
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	0	0	0
Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range from 0400 and Greater | Insurance, Other [Member] | Policyholder Account Balance, above Guaranteed Minimum Crediting Rate, Range from 0151 and Greater
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	$ 0	$ 0	$ 0
Minimum | Policyholder account balance, guaranteed minimum credit rating, range from 0201 to 0400
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance, Guaranteed Minimum Crediting Rate	2.01%
Minimum | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range from 0400 and Greater
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance, Guaranteed Minimum Crediting Rate	4.00%
Maximum | Policyholder account balance, guaranteed minimum credit rating, range from 0000 to 0200
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance, Guaranteed Minimum Crediting Rate	2.00%
Maximum | Policyholder account balance, guaranteed minimum credit rating, range from 0201 to 0400
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance, Guaranteed Minimum Crediting Rate	4.00%