Fair Value Measurements - Assets and liabilities measured and carried at fair value in the financial statements (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Assets:
Available for sale (AFS) fixed maturities	$ 10,095	$ 10,357
Trading fixed maturities	32	28
Equity securities, at fair value	1,010	1,042
Assets of managed investment entities	28,831	28,931
Total assets accounted for at fair value	16,584	16,723
Liabilities:
Liabilities of managed investment entities	24,779	23,919
Derivative liability	42	0
Total liabilities accounted for at fair value	5,399	5,243
Contingent consideration - acquisitions
Liabilities:
Contingent consideration	25	23
Other liabilities — derivatives
Liabilities:
Derivative liability	42
Variable interest entity, primary beneficiary
Assets:
Assets of managed investment entities	5,447	5,296
Liabilities:
Liabilities of managed investment entities	5,332	5,220
Fixed maturities
Assets:
Available for sale (AFS) fixed maturities	10,095	10,357
Trading fixed maturities	32	28
U.S. Government and government agencies
Assets:
Available for sale (AFS) fixed maturities	219	216
States, municipalities and political subdivisions
Assets:
Available for sale (AFS) fixed maturities	1,186	1,832
Foreign government
Assets:
Available for sale (AFS) fixed maturities	226	246
Residential MBS
Assets:
Available for sale (AFS) fixed maturities	1,598	960
Commercial MBS
Assets:
Available for sale (AFS) fixed maturities	85	104
Collateralized loan obligations
Assets:
Available for sale (AFS) fixed maturities	1,921	1,643
Other asset-backed securities
Assets:
Available for sale (AFS) fixed maturities	2,245	2,676
Corporate and other
Assets:
Available for sale (AFS) fixed maturities	2,615	2,680
Equity securities
Assets:
Equity securities, at fair value	1,010	1,042
Level 1
Assets:
Total assets accounted for at fair value	1,442	1,295
Liabilities:
Total liabilities accounted for at fair value	645	384
Level 1 | Contingent consideration - acquisitions
Liabilities:
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	659	390
Liabilities:
Liabilities of managed investment entities	645	384
Level 1 | Fixed maturities
Assets:
Available for sale (AFS) fixed maturities	227	226
Trading fixed maturities	0	0
Level 1 | U.S. Government and government agencies
Assets:
Available for sale (AFS) fixed maturities	219	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	8	11
Level 1 | Equity securities
Assets:
Equity securities, at fair value	556	679
Level 2
Assets:
Total assets accounted for at fair value	14,040	14,502
Liabilities:
Total liabilities accounted for at fair value	4,718	4,823
Level 2 | Contingent consideration - acquisitions
Liabilities:
Contingent consideration	0	0
Level 2 | Other liabilities — derivatives
Liabilities:
Derivative liability	42
Level 2 | Variable interest entity, primary beneficiary
Assets:
Assets of managed investment entities	4,777	4,893
Liabilities:
Liabilities of managed investment entities	4,676	4,823
Level 2 | Fixed maturities
Assets:
Available for sale (AFS) fixed maturities	9,204	9,531
Trading fixed maturities	32	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	1,181	1,791
Level 2 | Foreign government
Assets:
Available for sale (AFS) fixed maturities	226	246
Level 2 | Residential MBS
Assets:
Available for sale (AFS) fixed maturities	1,589	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	1,919	1,643
Level 2 | Other asset-backed securities
Assets:
Available for sale (AFS) fixed maturities	1,916	2,398
Level 2 | Corporate and other
Assets:
Available for sale (AFS) fixed maturities	2,288	2,402
Level 2 | Equity securities
Assets:
Equity securities, at fair value	27	50
Level 3
Assets:
Total assets accounted for at fair value	1,102	926
Liabilities:
Total liabilities accounted for at fair value	36	36
Level 3 | Contingent consideration - acquisitions
Liabilities:
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	11	13
Level 3 | Fixed maturities
Assets:
Available for sale (AFS) fixed maturities	664	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	5	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	9	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	329	278
Level 3 | Corporate and other
Assets:
Available for sale (AFS) fixed maturities	319	267
Level 3 | Equity securities
Assets:
Equity securities, at fair value	$ 427	$ 313