Fair Value Measurements - Assets and liabilities measured and carried at fair value in the financial statements (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Assets:
Available for sale (AFS) fixed maturities	$ 9,289	$ 9,084
Trading fixed maturities	26	24
Equity securities	944	889
Assets of managed investment entities	74,197	73,710
Liabilities:
Liabilities of managed investment entities	67,512	66,921
Total liabilities of continuing operations accounted for at fair value	5,045	4,914
Total assets of continuing operations accounted for at fair value	15,361	14,968
Annuity subsidiaries | Assets of discontinued annuity operations
Assets:
Variable annuity assets (separate accounts)	666	664
Liabilities:
Total assets of continuing operations accounted for at fair value	36,966	36,530
Annuity subsidiaries | Liabilities of discontinued annuity operations
Liabilities:
Total liabilities of continuing operations accounted for at fair value	3,964	3,943
Variable interest entity, primary beneficiary
Assets:
Assets of managed investment entities	5,102	4,971
Liabilities:
Liabilities of managed investment entities	5,045	4,914
Annuity benefits accumulated | Annuity subsidiaries | Liabilities of discontinued annuity operations
Liabilities:
Derivatives included in annuity benefits accumulated, long-term debt, and other liabilities	3,954	3,933
Other liabilities — derivatives | Annuity subsidiaries | Liabilities of discontinued annuity operations
Liabilities:
Derivatives included in annuity benefits accumulated, long-term debt, and other liabilities	10	10
Fixed maturities
Assets:
Available for sale (AFS) fixed maturities	9,289	9,084
Trading fixed maturities	26	24
Fixed maturities | Annuity subsidiaries | Assets of discontinued annuity operations
Assets:
Available for sale (AFS) fixed maturities	34,754	34,123
Trading fixed maturities	40	42
U.S. Government and government agencies
Assets:
Available for sale (AFS) fixed maturities	215	198
U.S. Government and government agencies | Annuity subsidiaries | Assets of discontinued annuity operations
Assets:
Available for sale (AFS) fixed maturities	42	44
States, municipalities and political subdivisions
Assets:
Available for sale (AFS) fixed maturities	2,167	2,312
States, municipalities and political subdivisions | Annuity subsidiaries | Assets of discontinued annuity operations
Assets:
Available for sale (AFS) fixed maturities	3,216	3,421
Foreign government
Assets:
Available for sale (AFS) fixed maturities	190	176
Foreign government | Annuity subsidiaries | Assets of discontinued annuity operations
Assets:
Available for sale (AFS) fixed maturities	34	35
Residential MBS
Assets:
Available for sale (AFS) fixed maturities	847	915
Residential MBS | Annuity subsidiaries | Assets of discontinued annuity operations
Assets:
Available for sale (AFS) fixed maturities	2,513	2,140
Commercial MBS
Assets:
Available for sale (AFS) fixed maturities	109	92
Commercial MBS | Annuity subsidiaries | Assets of discontinued annuity operations
Assets:
Available for sale (AFS) fixed maturities	636	698
Collateralized loan obligations
Assets:
Available for sale (AFS) fixed maturities	1,131	1,062
Collateralized loan obligations | Annuity subsidiaries | Assets of discontinued annuity operations
Assets:
Available for sale (AFS) fixed maturities	3,788	3,491
Other asset-backed securities
Assets:
Available for sale (AFS) fixed maturities	2,188	2,047
Other asset-backed securities | Annuity subsidiaries | Assets of discontinued annuity operations
Assets:
Available for sale (AFS) fixed maturities	5,204	5,176
Corporate and other
Assets:
Available for sale (AFS) fixed maturities	2,442	2,282
Corporate and other | Annuity subsidiaries | Assets of discontinued annuity operations
Assets:
Available for sale (AFS) fixed maturities	19,321	19,118
Equity securities
Assets:
Equity securities	944	889
Equity securities | Annuity subsidiaries | Assets of discontinued annuity operations
Assets:
Equity securities	624	774
Other assets | Annuity subsidiaries | Assets of discontinued annuity operations
Assets:
Derivatives including equity index call options and other assets	69	102
Level 1
Liabilities:
Total liabilities of continuing operations accounted for at fair value	285	215
Total assets of continuing operations accounted for at fair value	1,174	1,081
Level 1 | Annuity subsidiaries | Assets of discontinued annuity operations
Assets:
Variable annuity assets (separate accounts)	0	0
Liabilities:
Total assets of continuing operations accounted for at fair value	294	477
Level 1 | Annuity subsidiaries | Liabilities of discontinued annuity operations
Liabilities:
Total liabilities of continuing operations accounted for at fair value	0	0
Level 1 | Variable interest entity, primary beneficiary
Assets:
Assets of managed investment entities	288	217
Liabilities:
Liabilities of managed investment entities	285	215
Level 1 | Annuity benefits accumulated | Annuity subsidiaries | Liabilities of discontinued annuity operations
Liabilities:
Derivatives included in annuity benefits accumulated, long-term debt, and other liabilities	0	0
Level 1 | Other liabilities — derivatives | Annuity subsidiaries | Liabilities of discontinued annuity operations
Liabilities:
Derivatives included in annuity benefits accumulated, long-term debt, and other liabilities	0	0
Level 1 | Fixed maturities
Assets:
Available for sale (AFS) fixed maturities	216	199
Trading fixed maturities	0	0
Level 1 | Fixed maturities | Annuity subsidiaries | Assets of discontinued annuity operations
Assets:
Available for sale (AFS) fixed maturities	36	46
Trading fixed maturities	0	0
Level 1 | U.S. Government and government agencies
Assets:
Available for sale (AFS) fixed maturities	212	195
Level 1 | U.S. Government and government agencies | Annuity subsidiaries | Assets of discontinued annuity operations
Assets:
Available for sale (AFS) fixed maturities	6	6
Level 1 | States, municipalities and political subdivisions
Assets:
Available for sale (AFS) fixed maturities	0	0
Level 1 | States, municipalities and political subdivisions | Annuity subsidiaries | Assets of discontinued annuity operations
Assets:
Available for sale (AFS) fixed maturities	0	0
Level 1 | Foreign government
Assets:
Available for sale (AFS) fixed maturities	0	0
Level 1 | Foreign government | Annuity subsidiaries | Assets of discontinued annuity operations
Assets:
Available for sale (AFS) fixed maturities	0	0
Level 1 | Residential MBS
Assets:
Available for sale (AFS) fixed maturities	0	0
Level 1 | Residential MBS | Annuity subsidiaries | Assets of discontinued annuity operations
Assets:
Available for sale (AFS) fixed maturities	0	0
Level 1 | Commercial MBS
Assets:
Available for sale (AFS) fixed maturities	0	0
Level 1 | Commercial MBS | Annuity subsidiaries | Assets of discontinued annuity operations
Assets:
Available for sale (AFS) fixed maturities	0	0
Level 1 | Collateralized loan obligations
Assets:
Available for sale (AFS) fixed maturities	0	0
Level 1 | Collateralized loan obligations | Annuity subsidiaries | Assets of discontinued annuity operations
Assets:
Available for sale (AFS) fixed maturities	0	0
Level 1 | Other asset-backed securities
Assets:
Available for sale (AFS) fixed maturities	0	0
Level 1 | Other asset-backed securities | Annuity subsidiaries | Assets of discontinued annuity operations
Assets:
Available for sale (AFS) fixed maturities	0	0
Level 1 | Corporate and other
Assets:
Available for sale (AFS) fixed maturities	4	4
Level 1 | Corporate and other | Annuity subsidiaries | Assets of discontinued annuity operations
Assets:
Available for sale (AFS) fixed maturities	30	40
Level 1 | Equity securities
Assets:
Equity securities	670	665
Level 1 | Equity securities | Annuity subsidiaries | Assets of discontinued annuity operations
Assets:
Equity securities	258	431
Level 1 | Other assets | Annuity subsidiaries | Assets of discontinued annuity operations
Assets:
Derivatives including equity index call options and other assets	0	0
Level 2
Liabilities:
Total liabilities of continuing operations accounted for at fair value	4,746	4,678
Total assets of continuing operations accounted for at fair value	13,344	13,152
Level 2 | Annuity subsidiaries | Assets of discontinued annuity operations
Assets:
Variable annuity assets (separate accounts)	666	664
Liabilities:
Total assets of continuing operations accounted for at fair value	33,866	33,082
Level 2 | Annuity subsidiaries | Liabilities of discontinued annuity operations
Liabilities:
Total liabilities of continuing operations accounted for at fair value	10	10
Level 2 | Variable interest entity, primary beneficiary
Assets:
Assets of managed investment entities	4,800	4,733
Liabilities:
Liabilities of managed investment entities	4,746	4,678
Level 2 | Annuity benefits accumulated | Annuity subsidiaries | Liabilities of discontinued annuity operations
Liabilities:
Derivatives included in annuity benefits accumulated, long-term debt, and other liabilities	0	0
Level 2 | Other liabilities — derivatives | Annuity subsidiaries | Liabilities of discontinued annuity operations
Liabilities:
Derivatives included in annuity benefits accumulated, long-term debt, and other liabilities	10	10
Level 2 | Fixed maturities
Assets:
Available for sale (AFS) fixed maturities	8,471	8,347
Trading fixed maturities	26	24
Level 2 | Fixed maturities | Annuity subsidiaries | Assets of discontinued annuity operations
Assets:
Available for sale (AFS) fixed maturities	32,230	31,399
Trading fixed maturities	40	42
Level 2 | U.S. Government and government agencies
Assets:
Available for sale (AFS) fixed maturities	3	3
Level 2 | U.S. Government and government agencies | Annuity subsidiaries | Assets of discontinued annuity operations
Assets:
Available for sale (AFS) fixed maturities	21	23
Level 2 | States, municipalities and political subdivisions
Assets:
Available for sale (AFS) fixed maturities	2,128	2,273
Level 2 | States, municipalities and political subdivisions | Annuity subsidiaries | Assets of discontinued annuity operations
Assets:
Available for sale (AFS) fixed maturities	3,156	3,357
Level 2 | Foreign government
Assets:
Available for sale (AFS) fixed maturities	190	176
Level 2 | Foreign government | Annuity subsidiaries | Assets of discontinued annuity operations
Assets:
Available for sale (AFS) fixed maturities	34	35
Level 2 | Residential MBS
Assets:
Available for sale (AFS) fixed maturities	820	877
Level 2 | Residential MBS | Annuity subsidiaries | Assets of discontinued annuity operations
Assets:
Available for sale (AFS) fixed maturities	2,431	2,013
Level 2 | Commercial MBS
Assets:
Available for sale (AFS) fixed maturities	109	90
Level 2 | Commercial MBS | Annuity subsidiaries | Assets of discontinued annuity operations
Assets:
Available for sale (AFS) fixed maturities	635	687
Level 2 | Collateralized loan obligations
Assets:
Available for sale (AFS) fixed maturities	1,125	1,046
Level 2 | Collateralized loan obligations | Annuity subsidiaries | Assets of discontinued annuity operations
Assets:
Available for sale (AFS) fixed maturities	3,762	3,443
Level 2 | Other asset-backed securities
Assets:
Available for sale (AFS) fixed maturities	1,862	1,742
Level 2 | Other asset-backed securities | Annuity subsidiaries | Assets of discontinued annuity operations
Assets:
Available for sale (AFS) fixed maturities	4,277	4,108
Level 2 | Corporate and other
Assets:
Available for sale (AFS) fixed maturities	2,234	2,140
Level 2 | Corporate and other | Annuity subsidiaries | Assets of discontinued annuity operations
Assets:
Available for sale (AFS) fixed maturities	17,914	17,733
Level 2 | Equity securities
Assets:
Equity securities	47	48
Level 2 | Equity securities | Annuity subsidiaries | Assets of discontinued annuity operations
Assets:
Equity securities	48	50
Level 2 | Other assets | Annuity subsidiaries | Assets of discontinued annuity operations
Assets:
Derivatives including equity index call options and other assets	69	102
Level 3
Liabilities:
Total liabilities of continuing operations accounted for at fair value	14	21
Total assets of continuing operations accounted for at fair value	843	735
Level 3 | Annuity subsidiaries | Assets of discontinued annuity operations
Assets:
Variable annuity assets (separate accounts)	0	0
Liabilities:
Total assets of continuing operations accounted for at fair value	2,806	2,971
Level 3 | Annuity subsidiaries | Liabilities of discontinued annuity operations
Liabilities:
Total liabilities of continuing operations accounted for at fair value	3,954	3,933
Level 3 | Variable interest entity, primary beneficiary
Assets:
Assets of managed investment entities	14	21
Liabilities:
Liabilities of managed investment entities	14	21
Level 3 | Annuity benefits accumulated | Annuity subsidiaries | Liabilities of discontinued annuity operations
Liabilities:
Derivatives included in annuity benefits accumulated, long-term debt, and other liabilities	3,954	3,933
Level 3 | Other liabilities — derivatives | Annuity subsidiaries | Liabilities of discontinued annuity operations
Liabilities:
Derivatives included in annuity benefits accumulated, long-term debt, and other liabilities	0	0
Level 3 | Fixed maturities
Assets:
Available for sale (AFS) fixed maturities	602	538
Trading fixed maturities	0	0
Level 3 | Fixed maturities | Annuity subsidiaries | Assets of discontinued annuity operations
Assets:
Available for sale (AFS) fixed maturities	2,488	2,678
Trading fixed maturities	0	0
Level 3 | U.S. Government and government agencies
Assets:
Available for sale (AFS) fixed maturities	0	0
Level 3 | U.S. Government and government agencies | Annuity subsidiaries | Assets of discontinued annuity operations
Assets:
Available for sale (AFS) fixed maturities	15	15
Level 3 | States, municipalities and political subdivisions
Assets:
Available for sale (AFS) fixed maturities	39	39
Level 3 | States, municipalities and political subdivisions | Annuity subsidiaries | Assets of discontinued annuity operations
Assets:
Available for sale (AFS) fixed maturities	60	64
Level 3 | Foreign government
Assets:
Available for sale (AFS) fixed maturities	0	0
Level 3 | Foreign government | Annuity subsidiaries | Assets of discontinued annuity operations
Assets:
Available for sale (AFS) fixed maturities	0	0
Level 3 | Residential MBS
Assets:
Available for sale (AFS) fixed maturities	27	38
Level 3 | Residential MBS | Annuity subsidiaries | Assets of discontinued annuity operations
Assets:
Available for sale (AFS) fixed maturities	82	127
Level 3 | Commercial MBS
Assets:
Available for sale (AFS) fixed maturities	0	2
Level 3 | Commercial MBS | Annuity subsidiaries | Assets of discontinued annuity operations
Assets:
Available for sale (AFS) fixed maturities	1	11
Level 3 | Collateralized loan obligations
Assets:
Available for sale (AFS) fixed maturities	6	16
Level 3 | Collateralized loan obligations | Annuity subsidiaries | Assets of discontinued annuity operations
Assets:
Available for sale (AFS) fixed maturities	26	48
Level 3 | Other asset-backed securities
Assets:
Available for sale (AFS) fixed maturities	326	305
Level 3 | Other asset-backed securities | Annuity subsidiaries | Assets of discontinued annuity operations
Assets:
Available for sale (AFS) fixed maturities	927	1,068
Level 3 | Corporate and other
Assets:
Available for sale (AFS) fixed maturities	204	138
Level 3 | Corporate and other | Annuity subsidiaries | Assets of discontinued annuity operations
Assets:
Available for sale (AFS) fixed maturities	1,377	1,345
Level 3 | Equity securities
Assets:
Equity securities	227	176
Level 3 | Equity securities | Annuity subsidiaries | Assets of discontinued annuity operations
Assets:
Equity securities	318	293
Level 3 | Other assets | Annuity subsidiaries | Assets of discontinued annuity operations
Assets:
Derivatives including equity index call options and other assets	0	0
Call option | Equity index call options | Annuity subsidiaries | Assets of discontinued annuity operations
Assets:
Derivatives including equity index call options and other assets	813	825
Call option | Level 1 | Equity index call options | Annuity subsidiaries | Assets of discontinued annuity operations
Assets:
Derivatives including equity index call options and other assets	0	0
Call option | Level 2 | Equity index call options | Annuity subsidiaries | Assets of discontinued annuity operations
Assets:
Derivatives including equity index call options and other assets	813	825
Call option | Level 3 | Equity index call options | Annuity subsidiaries | Assets of discontinued annuity operations
Assets:
Derivatives including equity index call options and other assets	$ 0	$ 0