Policyholders' account balances (Guaranteed Minimum Crediting Rates) (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	$ 8,016	$ 7,462
Universal Life
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	1,809	1,876
Universal Life | Policyholder Account Balance, at Guaranteed Minimum Crediting Rate
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	685	579
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	615	319
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	395	923
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	114	55
Annuities [Member]
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	2,585	2,411
Annuities [Member] | Policyholder Account Balance, at Guaranteed Minimum Crediting Rate
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	911	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	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	1,628	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	46	0
Insurance, Other [Member]
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	2,354	2,502
Insurance, Other [Member] | Policyholder Account Balance, at Guaranteed Minimum Crediting Rate
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	1,685	1,160
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	56	540
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	182	256
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	431	546
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	587	540
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	427	475
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
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	46	29
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	114	36
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	1,754	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	80	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	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	1,628	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	46	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	986	1,556
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	367	782
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	6	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	182	228
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	431	546
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	1,209	1,314
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	245	82
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	615	319
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	349	894
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	0	19
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	831	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	831	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	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	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	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	1,368	941
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	1,318	373
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	50	540
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	0	28
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
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	13	22
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	13	22
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
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
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
Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range from 0400 and Greater | Annuities [Member]
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	0	0
Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range from 0400 and Greater | Annuities [Member] | Policyholder Account Balance, at Guaranteed Minimum Crediting Rate
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	0	0
Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range from 0400 and Greater | 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	0
Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range from 0400 and Greater | 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	0
Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range from 0400 and Greater | 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	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	0	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	0	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
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
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
Minimum | 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, Guaranteed Minimum Crediting Rate	2.01%	2.01%
Minimum | 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, Guaranteed Minimum Crediting Rate	2.01%	2.01%
Minimum | 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, Guaranteed Minimum Crediting Rate	2.01%	2.01%
Minimum | 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, Guaranteed Minimum Crediting Rate	4.00%	4.00%
Minimum | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range from 0400 and Greater | Annuities [Member]
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance, Guaranteed Minimum Crediting Rate	4.00%	4.00%
Minimum | 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, Guaranteed Minimum Crediting Rate	4.00%	4.00%
Maximum | 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, Guaranteed Minimum Crediting Rate	2.00%	2.00%
Maximum | 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, Guaranteed Minimum Crediting Rate	2.00%	2.00%
Maximum | 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, Guaranteed Minimum Crediting Rate	2.00%	2.00%
Maximum | 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, Guaranteed Minimum Crediting Rate	4.00%	4.00%
Maximum | 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, Guaranteed Minimum Crediting Rate	4.00%	4.00%
Maximum | 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, Guaranteed Minimum Crediting Rate	4.00%	4.00%