Fair Value of Financial Instruments - Schedule of Carrying Amounts of Assets and Liabilities at Estimated Fair Value Measured on a Recurring Basis (Details) - USD ($) $ in Millions	Mar. 31, 2025	Dec. 31, 2024
Assets
Fixed maturity securities available for sale	$ 49,824	$ 48,218
Derivative investments and reinsurance related embedded derivative, included in other assets	705	794
Market risk benefits asset	187	189
Total financial assets at fair value	1,396	1,433
Derivatives:
Market risk benefits liability	635	549
Level 1
Assets
Cash and cash equivalents	4,484	3,479
Derivative investments and reinsurance related embedded derivative, included in other assets	1	0
Investment in unconsolidated affiliates	0	0
Short term investments	1,106	2,995
Loan receivable, included in Prepaid expenses and other assets	0	0
Market risk benefits asset	0	0
Total financial assets at fair value	7,026	7,945
Derivatives:
Contingent consideration obligation, included in Accounts payable and accrued liabilities	0	0
Market risk benefits liability	0	0
Total financial liabilities at fair value	1	1
Level 2
Assets
Cash and cash equivalents	0	0
Derivative investments and reinsurance related embedded derivative, included in other assets	703	791
Investment in unconsolidated affiliates	0	0
Short term investments	15	18
Loan receivable, included in Prepaid expenses and other assets	0	0
Market risk benefits asset	0	0
Total financial assets at fair value	38,153	37,459
Derivatives:
Contingent consideration obligation, included in Accounts payable and accrued liabilities	0	0
Market risk benefits liability	0	0
Total financial liabilities at fair value	(78)	(99)
Level 3
Assets
Cash and cash equivalents	0	0
Derivative investments and reinsurance related embedded derivative, included in other assets	1	3
Investment in unconsolidated affiliates	272	272
Short term investments	40	37
Loan receivable, included in Prepaid expenses and other assets	11	11
Market risk benefits asset	187	189
Total financial assets at fair value	12,518	11,734
Derivatives:
Contingent consideration obligation, included in Accounts payable and accrued liabilities	64	74
Market risk benefits liability	635	549
Total financial liabilities at fair value	6,016	5,843
NAV
Assets
Total financial assets at fair value	22	57
Fair Value
Assets
Cash and cash equivalents	4,484	3,479
Derivative investments and reinsurance related embedded derivative, included in other assets	705	794
Investment in unconsolidated affiliates	272	272
Short term investments	1,161	3,050
Loan receivable, included in Prepaid expenses and other assets	11	11
Market risk benefits asset	187	189
Total financial assets at fair value	57,719	57,195
Derivatives:
Contingent consideration obligation, included in Accounts payable and accrued liabilities	64	74
Market risk benefits liability	635	549
Total financial liabilities at fair value	5,939	5,745
Indexed annuities/indexed universal life insurance ("IUL") embedded derivatives, included in Contractholder funds \| Level 1
Derivatives:
Derivative liability	0	0
Indexed annuities/indexed universal life insurance ("IUL") embedded derivatives, included in Contractholder funds \| Level 2
Derivatives:
Derivative liability	0	0
Indexed annuities/indexed universal life insurance ("IUL") embedded derivatives, included in Contractholder funds \| Level 3
Derivatives:
Derivative liability	5,316	5,220
Indexed annuities/indexed universal life insurance ("IUL") embedded derivatives, included in Contractholder funds \| Fair Value
Derivatives:
Derivative liability	5,316	5,220
Interest rate swaps \| Level 1
Derivatives:
Derivative liability	0	0
Interest rate swaps \| Level 2
Derivatives:
Derivative liability	0	10
Interest rate swaps \| Level 3
Derivatives:
Derivative liability	1	0
Interest rate swaps \| Fair Value
Derivatives:
Derivative liability	1	10
Equity options \| Level 1
Derivatives:
Derivative liability	1	1
Equity options \| Level 2
Derivatives:
Derivative liability	0	0
Equity options \| Level 3
Derivatives:
Derivative liability	0	0
Equity options \| Fair Value
Derivatives:
Derivative liability	1	1
Reinsurance related embedded derivatives \| Level 1
Derivatives:
Reinsurance related embedded derivatives, included in Funds withheld for reinsurance liabilities	0	0
Reinsurance related embedded derivatives \| Level 2
Derivatives:
Reinsurance related embedded derivatives, included in Funds withheld for reinsurance liabilities	(78)	(109)
Reinsurance related embedded derivatives \| Level 3
Derivatives:
Reinsurance related embedded derivatives, included in Funds withheld for reinsurance liabilities	0	0
Reinsurance related embedded derivatives \| Fair Value
Derivatives:
Reinsurance related embedded derivatives, included in Funds withheld for reinsurance liabilities	(78)	(109)
Asset-backed securities ("ABS")
Assets
Fixed maturity securities available for sale	16,268	15,656
Asset-backed securities ("ABS") \| Level 1
Assets
Fixed maturity securities available for sale	0	0
Asset-backed securities ("ABS") \| Level 2
Assets
Fixed maturity securities available for sale	7,420	7,513
Asset-backed securities ("ABS") \| Level 3
Assets
Fixed maturity securities available for sale	8,848	8,143
Asset-backed securities ("ABS") \| Fair Value
Assets
Fixed maturity securities available for sale	16,268	15,656
Commercial mortgage-backed securities
Assets
Fixed maturity securities available for sale	5,142	5,182
Commercial mortgage-backed securities \| Level 1
Assets
Fixed maturity securities available for sale	0	0
Commercial mortgage-backed securities \| Level 2
Assets
Fixed maturity securities available for sale	5,142	5,182
Commercial mortgage-backed securities \| Level 3
Assets
Fixed maturity securities available for sale	0	0
Commercial mortgage-backed securities \| Fair Value
Assets
Fixed maturity securities available for sale	5,142	5,182
Corporates
Assets
Fixed maturity securities available for sale	22,748	21,696
Corporates \| Level 1
Assets
Fixed maturity securities available for sale	40	41
Corporates \| Level 2
Assets
Fixed maturity securities available for sale	19,702	18,698
Corporates \| Level 3
Assets
Fixed maturity securities available for sale	3,006	2,957
Corporates \| Fair Value
Assets
Fixed maturity securities available for sale	22,748	21,696
Hybrids
Assets
Fixed maturity securities available for sale	512	581
Hybrids \| Level 1
Assets
Fixed maturity securities available for sale	35	35
Hybrids \| Level 2
Assets
Fixed maturity securities available for sale	471	546
Hybrids \| Level 3
Assets
Fixed maturity securities available for sale	6	0
Hybrids \| Fair Value
Assets
Fixed maturity securities available for sale	512	581
Municipals
Assets
Fixed maturity securities available for sale	1,410	1,386
Municipals \| Level 1
Assets
Fixed maturity securities available for sale	0	0
Municipals \| Level 2
Assets
Fixed maturity securities available for sale	1,406	1,386
Municipals \| Level 3
Assets
Fixed maturity securities available for sale	4	0
Municipals \| Fair Value
Assets
Fixed maturity securities available for sale	1,410	1,386
Residential mortgage-backed securities
Assets
Fixed maturity securities available for sale	2,748	2,796
Residential mortgage-backed securities \| Level 1
Assets
Fixed maturity securities available for sale	0	0
Residential mortgage-backed securities \| Level 2
Assets
Fixed maturity securities available for sale	2,745	2,793
Residential mortgage-backed securities \| Level 3
Assets
Fixed maturity securities available for sale	3	3
Residential mortgage-backed securities \| Fair Value
Assets
Fixed maturity securities available for sale	2,748	2,796
U.S. Government
Assets
Fixed maturity securities available for sale	672	637
U.S. Government \| Level 1
Assets
Fixed maturity securities available for sale	666	631
U.S. Government \| Level 2
Assets
Fixed maturity securities available for sale	6	6
U.S. Government \| Level 3
Assets
Fixed maturity securities available for sale	0	0
U.S. Government \| Fair Value
Assets
Fixed maturity securities available for sale	672	637
Foreign Governments
Assets
Fixed maturity securities available for sale	324	284
Foreign Governments \| Level 1
Assets
Fixed maturity securities available for sale	0	0
Foreign Governments \| Level 2
Assets
Fixed maturity securities available for sale	301	280
Foreign Governments \| Level 3
Assets
Fixed maturity securities available for sale	23	4
Foreign Governments \| Fair Value
Assets
Fixed maturity securities available for sale	324	284
Preferred securities
Assets
Equity and preferred securities	429	443
Preferred securities \| Level 1
Assets
Equity and preferred securities	179	189
Preferred securities \| Level 2
Assets
Equity and preferred securities	242	246
Preferred securities \| Level 3
Assets
Equity and preferred securities	8	8
Preferred securities \| Fair Value
Assets
Equity and preferred securities	429	443
Equity securities \| Level 1
Assets
Equity and preferred securities	515	575
Equity securities \| Level 2
Assets
Equity and preferred securities	0	0
Equity securities \| Level 3
Assets
Equity and preferred securities	10	10
Equity securities \| NAV
Assets
Equity and preferred securities	22	57
Equity securities \| Fair Value
Assets
Equity and preferred securities	547	642
Other long-term investments \| Level 1
Assets
Other long-term investments	0	0
Other long-term investments \| Level 2
Assets
Other long-term investments	0	0
Other long-term investments \| Level 3
Assets
Other long-term investments	32	32
Other long-term investments \| Fair Value
Assets
Other long-term investments	32	32
Other assets \| Level 1
Assets
Other assets	0	0
Other assets \| Level 2
Assets
Other assets	0	0
Other assets \| Level 3
Assets
Other assets	67	65
Other assets \| Fair Value
Assets
Other assets	$ 67	$ 65

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