Fair Value of Financial Instruments - Quantitative Information Regarding Significant Unobservable Inputs Used for Recurring Level 3 Fair Value Measurements of Financial Instruments (Details) $ in Millions	Mar. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, fair value	$ 1,338	$ 1,312
Liabilities, fair value	5,161	4,661
Third-Party Valuation \| Offered Quotes
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, fair value	9,138	8,365
Liabilities, fair value	19
Indexed annuity/ IUL embedded derivatives, included in contractholder funds \| Discounted Cash Flow
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Liabilities, fair value	4,679	$ 4,258
Contingent Consideration \| Discounted Cash Flow
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Liabilities, fair value	$ 57
Minimum \| Discounted Cash Flow \| EBITA Volatility
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Contingent consideration	0.3500
Minimum \| Discounted Cash Flow \| Counterparty Discount Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Contingent consideration	0.0700
Minimum \| Indexed annuity/ IUL embedded derivatives, included in contractholder funds \| Discounted Cash Flow \| Surrender Rates
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded derivative liability	0.0025	0.0025
Minimum \| Indexed annuity/ IUL embedded derivatives, included in contractholder funds \| Discounted Cash Flow \| Partial Withdrawals
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded derivative liability	0.0200	0.0200
Minimum \| Indexed annuity/ IUL embedded derivatives, included in contractholder funds \| Discounted Cash Flow \| Non-Performance Spread
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded derivative liability	0.0035	0.0038
Minimum \| Indexed annuity/ IUL embedded derivatives, included in contractholder funds \| Discounted Cash Flow \| Market Value of Option
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded derivative liability	0.0000	0.0000
Minimum \| Indexed annuity/ IUL embedded derivatives, included in contractholder funds \| Discounted Cash Flow \| Swap Rates
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded derivative liability		0.0384
Minimum \| Indexed annuity/ IUL embedded derivatives, included in contractholder funds \| Discounted Cash Flow \| Mortality Multiplier
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded derivative liability	1.0000	1.0000
Minimum \| Indexed annuity/ IUL embedded derivatives, included in contractholder funds \| Discounted Cash Flow \| Option Cost
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded derivative liability	0.0007	0.0007
Minimum \| Contingent Consideration \| Discounted Cash Flow \| Risk Adjusted Discount Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Contingent consideration	0.1350
Maximum \| Discounted Cash Flow \| EBITA Volatility
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Contingent consideration	0.3500
Maximum \| Discounted Cash Flow \| Counterparty Discount Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Contingent consideration	0.0700
Maximum \| Indexed annuity/ IUL embedded derivatives, included in contractholder funds \| Discounted Cash Flow \| Surrender Rates
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded derivative liability	0.7000	0.7000
Maximum \| Indexed annuity/ IUL embedded derivatives, included in contractholder funds \| Discounted Cash Flow \| Partial Withdrawals
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded derivative liability	0.3571	0.3448
Maximum \| Indexed annuity/ IUL embedded derivatives, included in contractholder funds \| Discounted Cash Flow \| Non-Performance Spread
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded derivative liability	0.0102	0.0110
Maximum \| Indexed annuity/ IUL embedded derivatives, included in contractholder funds \| Discounted Cash Flow \| Market Value of Option
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded derivative liability	0.2411	0.1893
Maximum \| Indexed annuity/ IUL embedded derivatives, included in contractholder funds \| Discounted Cash Flow \| Swap Rates
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded derivative liability		0.0526
Maximum \| Indexed annuity/ IUL embedded derivatives, included in contractholder funds \| Discounted Cash Flow \| Mortality Multiplier
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded derivative liability	1.0000	1.0000
Maximum \| Indexed annuity/ IUL embedded derivatives, included in contractholder funds \| Discounted Cash Flow \| Option Cost
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded derivative liability	0.0570	0.0548
Maximum \| Contingent Consideration \| Discounted Cash Flow \| Risk Adjusted Discount Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Contingent consideration	0.1350
Weighted Average \| Discounted Cash Flow \| EBITA Volatility
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Contingent consideration	0.3500
Weighted Average \| Discounted Cash Flow \| Counterparty Discount Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Contingent consideration	0.0700
Weighted Average \| Indexed annuity/ IUL embedded derivatives, included in contractholder funds \| Discounted Cash Flow \| Surrender Rates
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded derivative liability	0.0680	0.0683
Weighted Average \| Indexed annuity/ IUL embedded derivatives, included in contractholder funds \| Discounted Cash Flow \| Partial Withdrawals
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded derivative liability	0.0274	0.0274
Weighted Average \| Indexed annuity/ IUL embedded derivatives, included in contractholder funds \| Discounted Cash Flow \| Non-Performance Spread
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded derivative liability	0.0087	0.0096
Weighted Average \| Indexed annuity/ IUL embedded derivatives, included in contractholder funds \| Discounted Cash Flow \| Market Value of Option
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded derivative liability	0.0352	0.0263
Weighted Average \| Indexed annuity/ IUL embedded derivatives, included in contractholder funds \| Discounted Cash Flow \| Swap Rates
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded derivative liability		0.0455
Weighted Average \| Indexed annuity/ IUL embedded derivatives, included in contractholder funds \| Discounted Cash Flow \| Mortality Multiplier
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded derivative liability	1.0000	1.0000
Weighted Average \| Indexed annuity/ IUL embedded derivatives, included in contractholder funds \| Discounted Cash Flow \| Option Cost
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded derivative liability	0.0247	0.0238
Weighted Average \| Contingent Consideration \| Discounted Cash Flow \| Risk Adjusted Discount Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Contingent consideration	0.1350
Asset-backed securities \| Third-Party Valuation
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, fair value	$ 89	$ 57
Asset-backed securities \| Minimum \| Third-Party Valuation \| Discount rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt securities	0.0527	0.0509
Asset-backed securities \| Maximum \| Third-Party Valuation \| Discount rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt securities	0.0654	0.0695
Asset-backed securities \| Weighted Average \| Third-Party Valuation \| Discount rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt securities	0.0603	0.0600
Commercial mortgage-backed securities \| Third-Party Valuation
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, fair value	$ 1
Commercial mortgage-backed securities \| Minimum \| Third-Party Valuation \| Discount rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt securities	0.0722
Commercial mortgage-backed securities \| Maximum \| Third-Party Valuation \| Discount rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt securities	0.0690
Commercial mortgage-backed securities \| Weighted Average \| Third-Party Valuation \| Discount rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt securities	0.0784
Corporates \| Third-Party Valuation
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, fair value	$ 760	$ 787
Corporates \| Discounted Cash Flow
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, fair value	$ 4	$ 8
Corporates \| Minimum \| Third-Party Valuation \| Discount rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt securities	0.0416	0.0000
Corporates \| Minimum \| Discounted Cash Flow \| Discount rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt securities	0.4375	0.4400
Corporates \| Maximum \| Third-Party Valuation \| Discount rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt securities	0.1287	0.1287
Corporates \| Maximum \| Discounted Cash Flow \| Discount rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt securities	1.0000	1.0000
Corporates \| Weighted Average \| Third-Party Valuation \| Discount rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt securities	0.0706	0.0691
Corporates \| Weighted Average \| Discounted Cash Flow \| Discount rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt securities	0.5707	0.7520
Municipals \| Third-Party Valuation
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, fair value		$ 32
Municipals \| Minimum \| Third-Party Valuation \| Discount rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt securities		0.0625
Municipals \| Maximum \| Third-Party Valuation \| Discount rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt securities		0.0625
Municipals \| Weighted Average \| Third-Party Valuation \| Discount rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt securities		0.0625
Residential mortgage-backed securities \| Third-Party Valuation
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, fair value	$ 3	$ 3
Residential mortgage-backed securities \| Minimum \| Third-Party Valuation \| Discount rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt securities	0.0564	0.0546
Residential mortgage-backed securities \| Maximum \| Third-Party Valuation \| Discount rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt securities	0.0564	0.0546
Residential mortgage-backed securities \| Weighted Average \| Third-Party Valuation \| Discount rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt securities	0.0564	0.0546
Foreign Governments \| Third-Party Valuation
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, fair value	$ 5	$ 16
Foreign Governments \| Minimum \| Third-Party Valuation \| Discount rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt securities	0.0677	0.0694
Foreign Governments \| Maximum \| Third-Party Valuation \| Discount rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt securities	0.0677	0.0768
Foreign Governments \| Weighted Average \| Third-Party Valuation \| Discount rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt securities	0.0677	0.0745
Investment in unconsolidated affiliates \| Broker quoted/Market Comparable
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, fair value		$ 285
Investment in unconsolidated affiliates \| Minimum \| Broker quoted/Market Comparable \| EBITDA Multiple
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Investment in unconsolidated affiliate		4.4
Investment in unconsolidated affiliates \| Maximum \| Broker quoted/Market Comparable \| EBITDA Multiple
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Investment in unconsolidated affiliate		31.8
Investment in unconsolidated affiliates \| Weighted Average \| Broker quoted/Market Comparable \| EBITDA Multiple
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Investment in unconsolidated affiliate		23.2
Investment in unconsolidated affiliates \| Affiliated Entity \| Broker quoted/Market Comparable
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, fair value	$ 343
Preferred securities \| Discounted Cash Flow
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, fair value		$ 1
Preferred securities \| Affiliated Entity \| Discounted Cash Flow
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, fair value	$ 1
Preferred securities \| Affiliated Entity \| Discounted Cash Flow \| Discount rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Preferred/Equity securities		1.0000
Preferred securities \| Affiliated Entity \| Minimum \| Discounted Cash Flow \| Discount rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Preferred/Equity securities	1.0000
Preferred securities \| Affiliated Entity \| Maximum \| Discounted Cash Flow \| Discount rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Preferred/Equity securities	1.0000
Preferred securities \| Affiliated Entity \| Weighted Average \| Discounted Cash Flow \| Discount rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Preferred/Equity securities	1.0000
Equity securities \| Discounted Cash Flow
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, fair value		$ 7
Equity securities \| Minimum \| Broker quoted/Market Comparable \| EBITDA Multiple
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Preferred/Equity securities	6
Equity securities \| Maximum \| Broker quoted/Market Comparable \| EBITDA Multiple
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Preferred/Equity securities	6
Equity securities \| Weighted Average \| Broker quoted/Market Comparable \| EBITDA Multiple
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Preferred/Equity securities	6
Equity securities \| Affiliated Entity \| Discounted Cash Flow
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, fair value	$ 7
Equity securities \| Affiliated Entity \| Minimum \| Discounted Cash Flow \| Discount rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Preferred/Equity securities	0.1090	0.1150
Equity securities \| Affiliated Entity \| Maximum \| Discounted Cash Flow \| Discount rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Preferred/Equity securities	0.1090	0.1150
Equity securities \| Affiliated Entity \| Weighted Average \| Discounted Cash Flow \| Discount rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Preferred/Equity securities	0.1090	0.1150
Available-for-sale embedded derivative \| Black Scholes model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, fair value	$ 30	$ 28
Available-for-sale embedded derivative \| Black Scholes model \| Market Value of AnchorPath Fund
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded derivative asset	1.0000	1.0000
Market risk benefits asset \| Discounted Cash Flow
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, fair value	$ 95	$ 88
Market risk benefits asset \| Minimum \| Discounted Cash Flow \| Mortality
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market risk benefit	1.0000	1.0000
Market risk benefits asset \| Minimum \| Discounted Cash Flow \| Surrender Rates
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market risk benefit	0.0025	0.0025
Market risk benefits asset \| Minimum \| Discounted Cash Flow \| Partial Withdrawals
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market risk benefit	0.0200	0
Market risk benefits asset \| Minimum \| Discounted Cash Flow \| Non-Performance Spread
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market risk benefit	0.0035	0.0038
Market risk benefits asset \| Minimum \| Discounted Cash Flow \| GMWB Utilization
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market risk benefit	0.5000	0.5000
Market risk benefits asset \| Maximum \| Discounted Cash Flow \| Mortality
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market risk benefit	1.0000	1.0000
Market risk benefits asset \| Maximum \| Discounted Cash Flow \| Surrender Rates
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market risk benefit	0.1000	0.1000
Market risk benefits asset \| Maximum \| Discounted Cash Flow \| Partial Withdrawals
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market risk benefit	0.2041	0.2326
Market risk benefits asset \| Maximum \| Discounted Cash Flow \| Non-Performance Spread
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market risk benefit	0.0102	0.0110
Market risk benefits asset \| Maximum \| Discounted Cash Flow \| GMWB Utilization
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market risk benefit	0.6000	0.6000
Market risk benefits asset \| Weighted Average \| Discounted Cash Flow \| Mortality
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market risk benefit	1.0000	1.0000
Market risk benefits asset \| Weighted Average \| Discounted Cash Flow \| Surrender Rates
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market risk benefit	0.0513	0.0522
Market risk benefits asset \| Weighted Average \| Discounted Cash Flow \| Partial Withdrawals
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market risk benefit	0.0250	0.0250
Market risk benefits asset \| Weighted Average \| Discounted Cash Flow \| Non-Performance Spread
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market risk benefit	0.0087	0.0096
Market risk benefits asset \| Weighted Average \| Discounted Cash Flow \| GMWB Utilization
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market risk benefit	0.5081	0.5081
Market risk benefits liability \| Discounted Cash Flow
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Liabilities, fair value	$ 425	$ 403
Market risk benefits liability \| Minimum \| Discounted Cash Flow \| Mortality
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market risk benefit	1.0000	1.0000
Market risk benefits liability \| Minimum \| Discounted Cash Flow \| Surrender Rates
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market risk benefit	0.0025	0.0025
Market risk benefits liability \| Minimum \| Discounted Cash Flow \| Partial Withdrawals
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market risk benefit	0.0200	0.0000
Market risk benefits liability \| Minimum \| Discounted Cash Flow \| Non-Performance Spread
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market risk benefit	0.0035	0.0038
Market risk benefits liability \| Minimum \| Discounted Cash Flow \| GMWB Utilization
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market risk benefit	0.5000	0.5000
Market risk benefits liability \| Maximum \| Discounted Cash Flow \| Mortality
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market risk benefit	1.0000	1.0000
Market risk benefits liability \| Maximum \| Discounted Cash Flow \| Surrender Rates
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market risk benefit	0.1000	0.1000
Market risk benefits liability \| Maximum \| Discounted Cash Flow \| Partial Withdrawals
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market risk benefit	0.2041	0.2326
Market risk benefits liability \| Maximum \| Discounted Cash Flow \| Non-Performance Spread
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market risk benefit	0.0102	0.0110
Market risk benefits liability \| Maximum \| Discounted Cash Flow \| GMWB Utilization
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market risk benefit	0.6000	0.6000
Market risk benefits liability \| Weighted Average \| Discounted Cash Flow \| Mortality
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market risk benefit	1.0000	1.0000
Market risk benefits liability \| Weighted Average \| Discounted Cash Flow \| Surrender Rates
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market risk benefit	0.0513	0.0522
Market risk benefits liability \| Weighted Average \| Discounted Cash Flow \| Partial Withdrawals
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market risk benefit	0.0250	0.0250
Market risk benefits liability \| Weighted Average \| Discounted Cash Flow \| Non-Performance Spread
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market risk benefit	0.0087	0.0096
Market risk benefits liability \| Weighted Average \| Discounted Cash Flow \| GMWB Utilization
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market risk benefit	0.5081	0.5081

Fair Value of Financial Instruments - Quantitative Information Regarding Significant Unobservable Inputs Used for Recurring Level 3 Fair Value Measurements of Financial Instruments (Details)
$ in Millions