Fair Value Measurements - Assets and liabilities measured and carried at fair value in the financial statements (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Assets:
Available for sale (AFS) fixed maturities	$ 10,357	$ 9,084
Trading fixed maturities	28	24
Equity securities, at fair value	1,042	889
Assets of managed investment entities	28,931	73,710
Total assets accounted for at fair value	16,723	14,968
Liabilities:
Liabilities of managed investment entities	23,919	66,921
Total liabilities accounted for at fair value	5,243	4,914
Contingent consideration - acquisitions
Liabilities:
Contingent consideration	23
Variable interest entity, primary beneficiary
Assets:
Assets of managed investment entities	5,296	4,971
Liabilities:
Liabilities of managed investment entities	5,220	4,914
Fixed maturities
Assets:
Available for sale (AFS) fixed maturities	10,357	9,084
Trading fixed maturities	28	24
U.S. Government and government agencies
Assets:
Available for sale (AFS) fixed maturities	216	198
States, municipalities and political subdivisions
Assets:
Available for sale (AFS) fixed maturities	1,832	2,312
Foreign government
Assets:
Available for sale (AFS) fixed maturities	246	176
Residential MBS
Assets:
Available for sale (AFS) fixed maturities	960	915
Commercial MBS
Assets:
Available for sale (AFS) fixed maturities	104	92
Collateralized loan obligations
Assets:
Available for sale (AFS) fixed maturities	1,643	1,062
Other asset-backed securities
Assets:
Available for sale (AFS) fixed maturities	2,676	2,047
Corporate and other
Assets:
Available for sale (AFS) fixed maturities	2,680	2,282
Equity securities
Assets:
Equity securities, at fair value	1,042	889
Level 1
Assets:
Total assets accounted for at fair value	1,295	1,081
Liabilities:
Total liabilities accounted for at fair value	384	215
Level 1 \| Contingent consideration - acquisitions
Liabilities:
Contingent consideration	0
Level 1 \| Variable interest entity, primary beneficiary
Assets:
Assets of managed investment entities	390	217
Liabilities:
Liabilities of managed investment entities	384	215
Level 1 \| Fixed maturities
Assets:
Available for sale (AFS) fixed maturities	226	199
Trading fixed maturities	0	0
Level 1 \| U.S. Government and government agencies
Assets:
Available for sale (AFS) fixed maturities	215	195
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	11	4
Level 1 \| Equity securities
Assets:
Equity securities, at fair value	679	665
Level 2
Assets:
Total assets accounted for at fair value	14,502	13,152
Liabilities:
Total liabilities accounted for at fair value	4,823	4,678
Level 2 \| Contingent consideration - acquisitions
Liabilities:
Contingent consideration	0
Level 2 \| Variable interest entity, primary beneficiary
Assets:
Assets of managed investment entities	4,893	4,733
Liabilities:
Liabilities of managed investment entities	4,823	4,678
Level 2 \| Fixed maturities
Assets:
Available for sale (AFS) fixed maturities	9,531	8,347
Trading fixed maturities	28	24
Level 2 \| U.S. Government and government agencies
Assets:
Available for sale (AFS) fixed maturities	1	3
Level 2 \| States, municipalities and political subdivisions
Assets:
Available for sale (AFS) fixed maturities	1,791	2,273
Level 2 \| Foreign government
Assets:
Available for sale (AFS) fixed maturities	246	176
Level 2 \| Residential MBS
Assets:
Available for sale (AFS) fixed maturities	946	877
Level 2 \| Commercial MBS
Assets:
Available for sale (AFS) fixed maturities	104	90
Level 2 \| Collateralized loan obligations
Assets:
Available for sale (AFS) fixed maturities	1,643	1,046
Level 2 \| Other asset-backed securities
Assets:
Available for sale (AFS) fixed maturities	2,398	1,742
Level 2 \| Corporate and other
Assets:
Available for sale (AFS) fixed maturities	2,402	2,140
Level 2 \| Equity securities
Assets:
Equity securities, at fair value	50	48
Level 3
Assets:
Total assets accounted for at fair value	926	735
Liabilities:
Total liabilities accounted for at fair value	36	21
Level 3 \| Contingent consideration - acquisitions
Liabilities:
Contingent consideration	23
Level 3 \| Variable interest entity, primary beneficiary
Assets:
Assets of managed investment entities	13	21
Liabilities:
Liabilities of managed investment entities	13	21
Level 3 \| Fixed maturities
Assets:
Available for sale (AFS) fixed maturities	600	538
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	41	39
Level 3 \| Foreign government
Assets:
Available for sale (AFS) fixed maturities	0	0
Level 3 \| Residential MBS
Assets:
Available for sale (AFS) fixed maturities	14	38
Level 3 \| Commercial MBS
Assets:
Available for sale (AFS) fixed maturities	0	2
Level 3 \| Collateralized loan obligations
Assets:
Available for sale (AFS) fixed maturities	0	16
Level 3 \| Other asset-backed securities
Assets:
Available for sale (AFS) fixed maturities	278	305
Level 3 \| Corporate and other
Assets:
Available for sale (AFS) fixed maturities	267	138
Level 3 \| Equity securities
Assets:
Equity securities, at fair value	$ 313	$ 176

Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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