Fair Value Measurements - Assets and liabilities measured and carried at fair value in the financial statements (Details) - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Assets:
Available for sale (AFS) fixed maturities	$ 10,034	$ 10,357
Trading fixed maturities	30	28
Equity securities	996	1,042
Assets of managed investment entities	29,532	28,931
Total assets accounted for at fair value	16,159	16,723
Liabilities:
Liabilities of managed investment entities	25,600	23,919
Total liabilities accounted for at fair value	5,073	5,243
Contingent consideration — acquisitions
Liabilities:
Fair value of potential contingent consideration	25	23
Contingent consideration — acquisitions | Verikai, Inc.
Liabilities:
Fair value of potential contingent consideration	23
Other liabilities — derivatives
Liabilities:
Derivative liability	46
Variable interest entity, primary beneficiary
Assets:
Assets of managed investment entities	5,099	5,296
Liabilities:
Liabilities of managed investment entities	5,002	5,220
Fixed maturities
Assets:
Available for sale (AFS) fixed maturities	10,034	10,357
Trading fixed maturities	30	28
U.S. government and government agencies
Assets:
Available for sale (AFS) fixed maturities	214	216
States, municipalities and political subdivisions
Assets:
Available for sale (AFS) fixed maturities	1,258	1,832
Foreign government
Assets:
Available for sale (AFS) fixed maturities	223	246
Residential MBS
Assets:
Available for sale (AFS) fixed maturities	1,604	960
Commercial MBS
Assets:
Available for sale (AFS) fixed maturities	85	104
Collateralized loan obligations
Assets:
Available for sale (AFS) fixed maturities	1,806	1,643
Other asset-backed securities
Assets:
Available for sale (AFS) fixed maturities	2,271	2,676
Corporate and other
Assets:
Available for sale (AFS) fixed maturities	2,573	2,680
Equity securities
Assets:
Equity securities	996	1,042
Level 1
Assets:
Total assets accounted for at fair value	1,090	1,295
Liabilities:
Total liabilities accounted for at fair value	291	384
Level 1 | Contingent consideration — acquisitions
Liabilities:
Fair value of potential contingent consideration	0	0
Level 1 | Other liabilities — derivatives
Liabilities:
Derivative liability	0
Level 1 | Variable interest entity, primary beneficiary
Assets:
Assets of managed investment entities	296	390
Liabilities:
Liabilities of managed investment entities	291	384
Level 1 | Fixed maturities
Assets:
Available for sale (AFS) fixed maturities	224	226
Trading fixed maturities	0	0
Level 1 | U.S. government and government agencies
Assets:
Available for sale (AFS) fixed maturities	214	215
Level 1 | States, municipalities and political subdivisions
Assets:
Available for sale (AFS) fixed maturities	0	0
Level 1 | Foreign government
Assets:
Available for sale (AFS) fixed maturities	0	0
Level 1 | Residential MBS
Assets:
Available for sale (AFS) fixed maturities	0	0
Level 1 | Commercial MBS
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 | Other asset-backed securities
Assets:
Available for sale (AFS) fixed maturities	0	0
Level 1 | Corporate and other
Assets:
Available for sale (AFS) fixed maturities	10	11
Level 1 | Equity securities
Assets:
Equity securities	570	679
Level 2
Assets:
Total assets accounted for at fair value	14,067	14,502
Liabilities:
Total liabilities accounted for at fair value	4,747	4,823
Level 2 | Contingent consideration — acquisitions
Liabilities:
Fair value of potential contingent consideration	0	0
Level 2 | Other liabilities — derivatives
Liabilities:
Derivative liability	46
Level 2 | Variable interest entity, primary beneficiary
Assets:
Assets of managed investment entities	4,792	4,893
Liabilities:
Liabilities of managed investment entities	4,701	4,823
Level 2 | Fixed maturities
Assets:
Available for sale (AFS) fixed maturities	9,203	9,531
Trading fixed maturities	30	28
Level 2 | U.S. government and government agencies
Assets:
Available for sale (AFS) fixed maturities	0	1
Level 2 | States, municipalities and political subdivisions
Assets:
Available for sale (AFS) fixed maturities	1,257	1,791
Level 2 | Foreign government
Assets:
Available for sale (AFS) fixed maturities	223	246
Level 2 | Residential MBS
Assets:
Available for sale (AFS) fixed maturities	1,596	946
Level 2 | Commercial MBS
Assets:
Available for sale (AFS) fixed maturities	85	104
Level 2 | Collateralized loan obligations
Assets:
Available for sale (AFS) fixed maturities	1,804	1,643
Level 2 | Other asset-backed securities
Assets:
Available for sale (AFS) fixed maturities	1,970	2,398
Level 2 | Corporate and other
Assets:
Available for sale (AFS) fixed maturities	2,268	2,402
Level 2 | Equity securities
Assets:
Equity securities	42	50
Level 3
Assets:
Total assets accounted for at fair value	1,002	926
Liabilities:
Total liabilities accounted for at fair value	35	36
Level 3 | Contingent consideration — acquisitions
Liabilities:
Fair value of potential contingent consideration	25	23
Level 3 | Other liabilities — derivatives
Liabilities:
Derivative liability	0
Level 3 | Variable interest entity, primary beneficiary
Assets:
Assets of managed investment entities	11	13
Liabilities:
Liabilities of managed investment entities	10	13
Level 3 | Fixed maturities
Assets:
Available for sale (AFS) fixed maturities	607	600
Trading fixed maturities	0	0
Level 3 | U.S. government and government agencies
Assets:
Available for sale (AFS) fixed maturities	0	0
Level 3 | States, municipalities and political subdivisions
Assets:
Available for sale (AFS) fixed maturities	1	41
Level 3 | Foreign government
Assets:
Available for sale (AFS) fixed maturities	0	0
Level 3 | Residential MBS
Assets:
Available for sale (AFS) fixed maturities	8	14
Level 3 | Commercial MBS
Assets:
Available for sale (AFS) fixed maturities	0	0
Level 3 | Collateralized loan obligations
Assets:
Available for sale (AFS) fixed maturities	2	0
Level 3 | Other asset-backed securities
Assets:
Available for sale (AFS) fixed maturities	301	278
Level 3 | Corporate and other
Assets:
Available for sale (AFS) fixed maturities	295	267
Level 3 | Equity securities
Assets:
Equity securities	$ 384	$ 313