Fair Value of Financial Instruments - Schedule of Quantitative Information Regarding Significant Unobservable Inputs Used for Recurring Level 3 Fair Value Measurements of Financial Instruments (Details) $ in Millions	Sep. 30, 2026 USD ($)	Dec. 31, 2025 USD ($)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, fair value	$ 2,270	$ 1,771
Liabilities, fair value	7,362	7,517
Third-Party Valuation \| Offered Quotes
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, fair value	14,300
Liabilities, fair value	19
Market Comparable Company Analysis \| Offered Quotes
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, fair value		12,596
Liabilities, fair value		9
Indexed annuities/IUL embedded derivatives, included in Contractholder funds \| Discounted Cash Flow
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Liabilities, fair value	$ 6,456	$ 6,542
Indexed annuities/IUL embedded derivatives, included in Contractholder funds \| Minimum \| Discounted Cash Flow \| Market Value of Option
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded derivative asset	0.0000	0.0000
Embedded derivative liability	0.0000	0.0000
Indexed annuities/IUL embedded derivatives, included in Contractholder funds \| Minimum \| Discounted Cash Flow \| Mortality Multiplier
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded derivative asset	0.7500	0.8000
Embedded derivative liability	0.7500	0.8000
Indexed annuities/IUL embedded derivatives, included in Contractholder funds \| Minimum \| Discounted Cash Flow \| Surrender Rates
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded derivative asset	0.0025	0.0025
Embedded derivative liability	0.0025	0.0025
Indexed annuities/IUL embedded derivatives, included in Contractholder funds \| Minimum \| Discounted Cash Flow \| Partial Withdrawal Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded derivative asset	0.0200	0.0200
Embedded derivative liability	0.0200	0.0200
Indexed annuities/IUL embedded derivatives, included in Contractholder funds \| Minimum \| Discounted Cash Flow \| Non-Performance Spread
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded derivative asset	0.0085	0.0053
Embedded derivative liability	0.0046	0.0043
Indexed annuities/IUL embedded derivatives, included in Contractholder funds \| Minimum \| Discounted Cash Flow \| Option Cost
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded derivative asset	0.0056	0.0139
Embedded derivative liability	0.0050	0.0050
Indexed annuities/IUL embedded derivatives, included in Contractholder funds \| Maximum \| Discounted Cash Flow \| Market Value of Option
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded derivative asset	0.2099	0.3177
Embedded derivative liability	0.1882	0.4013
Indexed annuities/IUL embedded derivatives, included in Contractholder funds \| Maximum \| Discounted Cash Flow \| Mortality Multiplier
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded derivative asset	1.2000	1.1500
Embedded derivative liability	1.2000	1.1500
Indexed annuities/IUL embedded derivatives, included in Contractholder funds \| Maximum \| Discounted Cash Flow \| Surrender Rates
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded derivative asset	0.3000	0.5000
Embedded derivative liability	0.7000	0.5000
Indexed annuities/IUL embedded derivatives, included in Contractholder funds \| Maximum \| Discounted Cash Flow \| Partial Withdrawal Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded derivative asset	0.2564	0.0650
Embedded derivative liability	0.3704	0.3571
Indexed annuities/IUL embedded derivatives, included in Contractholder funds \| Maximum \| Discounted Cash Flow \| Non-Performance Spread
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded derivative asset	0.0211	0.0115
Embedded derivative liability	0.0095	0.0085
Indexed annuities/IUL embedded derivatives, included in Contractholder funds \| Maximum \| Discounted Cash Flow \| Option Cost
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded derivative asset	0.0530	0.0530
Embedded derivative liability	0.0555	0.0609
Indexed annuities/IUL embedded derivatives, included in Contractholder funds \| Weighted Average \| Discounted Cash Flow \| Market Value of Option
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded derivative asset	0.0237	0.0274
Embedded derivative liability	0.0316	0.0384
Indexed annuities/IUL embedded derivatives, included in Contractholder funds \| Weighted Average \| Discounted Cash Flow \| Mortality Multiplier
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded derivative asset	0.9750	1.0000
Embedded derivative liability	0.9750	1.0000
Indexed annuities/IUL embedded derivatives, included in Contractholder funds \| Weighted Average \| Discounted Cash Flow \| Surrender Rates
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded derivative asset	0.0348	0.0333
Embedded derivative liability	0.0735	0.0668
Indexed annuities/IUL embedded derivatives, included in Contractholder funds \| Weighted Average \| Discounted Cash Flow \| Partial Withdrawal Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded derivative asset	0.0251	0.0222
Embedded derivative liability	0.0268	0.0269
Indexed annuities/IUL embedded derivatives, included in Contractholder funds \| Weighted Average \| Discounted Cash Flow \| Non-Performance Spread
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded derivative asset	0.0144	0.0090
Embedded derivative liability	0.0079	0.0064
Indexed annuities/IUL embedded derivatives, included in Contractholder funds \| Weighted Average \| Discounted Cash Flow \| Option Cost
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded derivative asset	0.0234	0.0198
Embedded derivative liability	0.0286	0.0278
Contingent consideration, included in Accounts payable and accrued liabilities \| Discounted Cash Flow
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Liabilities, fair value		$ 72
Contingent consideration, included in Accounts payable and accrued liabilities \| Minimum \| Discounted Cash Flow \| Counterparty Discount Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Contingent consideration liability		0.1150
Contingent consideration, included in Accounts payable and accrued liabilities \| Minimum \| Discounted Cash Flow \| EBITDA Volatility
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Contingent consideration liability		0.3500
Contingent consideration, included in Accounts payable and accrued liabilities \| Minimum \| Discounted Cash Flow \| Counterparty Discount Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Contingent consideration liability		0.0630
Contingent consideration, included in Accounts payable and accrued liabilities \| Maximum \| Discounted Cash Flow \| Counterparty Discount Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Contingent consideration liability		0.1150
Contingent consideration, included in Accounts payable and accrued liabilities \| Maximum \| Discounted Cash Flow \| EBITDA Volatility
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Contingent consideration liability		0.3500
Contingent consideration, included in Accounts payable and accrued liabilities \| Maximum \| Discounted Cash Flow \| Counterparty Discount Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Contingent consideration liability		0.0630
Contingent consideration, included in Accounts payable and accrued liabilities \| Weighted Average \| Discounted Cash Flow \| Counterparty Discount Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Contingent consideration liability		0.1150
Contingent consideration, included in Accounts payable and accrued liabilities \| Weighted Average \| Discounted Cash Flow \| EBITDA Volatility
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Contingent consideration liability		0.3500
Contingent consideration, included in Accounts payable and accrued liabilities \| Weighted Average \| Discounted Cash Flow \| Counterparty Discount Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Contingent consideration liability		0.0630
Asset-backed securities \| Third-Party Valuation
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, fair value	$ 156	$ 92
Asset-backed securities \| Minimum \| Third-Party Valuation \| Discount Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt securities	0.0611	0.0436
Asset-backed securities \| Maximum \| Third-Party Valuation \| Discount Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt securities	0.1230	0.0715
Asset-backed securities \| Weighted Average \| Third-Party Valuation \| Discount Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt securities	0.0770	0.0580
Corporates \| Third-Party Valuation
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, fair value	$ 560	$ 649
Corporates \| Minimum \| Third-Party Valuation \| Discount Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt securities	0.0430	0.0345
Corporates \| Maximum \| Third-Party Valuation \| Discount Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt securities	0.0906	0.0868
Corporates \| Weighted Average \| Third-Party Valuation \| Discount Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt securities	0.0659	0.0584
Municipals \| Third-Party Valuation
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, fair value	$ 3	$ 3
Municipals \| Minimum \| Third-Party Valuation \| Discount Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt securities	0.0630	0.0494
Municipals \| Maximum \| Third-Party Valuation \| Discount Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt securities	0.0630	0.0494
Municipals \| Weighted Average \| Third-Party Valuation \| Discount Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt securities	0.0630	0.0494
Residential mortgage-backed securities \| Third-Party Valuation
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, fair value		$ 3
Residential mortgage-backed securities \| Minimum \| Third-Party Valuation \| Discount Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt securities		0.0541
Residential mortgage-backed securities \| Maximum \| Third-Party Valuation \| Discount Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt securities		0.0541
Residential mortgage-backed securities \| Weighted Average \| Third-Party Valuation \| Discount Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt securities		0.0541
Foreign Governments \| Third-Party Valuation
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, fair value	$ 5	$ 5
Foreign Governments \| Minimum \| Third-Party Valuation \| Discount Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt securities	0.0580	0.0573
Foreign Governments \| Maximum \| Third-Party Valuation \| Discount Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt securities	0.0580	0.0573
Foreign Governments \| Weighted Average \| Third-Party Valuation \| Discount Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt securities	0.0580	0.0573
Investments in unconsolidated affiliates \| Market Comparable Company Analysis
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, fair value	$ 256	$ 270
Investments in unconsolidated affiliates \| Minimum \| Market Comparable Company Analysis \| EBITDA Multiple
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Investment in unconsolidated affiliates	8.00	7.4
Investments in unconsolidated affiliates \| Maximum \| Market Comparable Company Analysis \| EBITDA Multiple
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Investment in unconsolidated affiliates	14.50	15.5
Investments in unconsolidated affiliates \| Weighted Average \| Market Comparable Company Analysis \| EBITDA Multiple
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Investment in unconsolidated affiliates	11.58	12.1
Available-for-sale embedded derivative \| Black Scholes Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, fair value		$ 41
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
Indexed annuities/IUL ceded embedded derivatives \| Black Scholes Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, fair value		$ 399
Indexed annuities/IUL ceded embedded derivatives \| Discounted Cash Flow
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, fair value	$ 947
Loan receivable \| Discounted Cash Flow
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, fair value		$ 24
Loan receivable \| Minimum \| Discounted Cash Flow \| Counterparty Discount Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loan receivable		0.0635
Loan receivable \| Minimum \| Discounted Cash Flow \| Collateral Volatility
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loan receivable		0.3500
Loan receivable \| Maximum \| Discounted Cash Flow \| Counterparty Discount Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loan receivable		0.0635
Loan receivable \| Maximum \| Discounted Cash Flow \| Collateral Volatility
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loan receivable		0.3500
Loan receivable \| Weighted Average \| Discounted Cash Flow \| Counterparty Discount Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loan receivable		0.0635
Loan receivable \| Weighted Average \| Discounted Cash Flow \| Collateral Volatility
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loan receivable		0.3500
Market risk benefits asset \| Discounted Cash Flow
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, fair value	$ 343	$ 285
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 Withdrawal Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market risk benefit	0.0200	0.0000
Market risk benefits asset \| Minimum \| Discounted Cash Flow \| Non-Performance Spread
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market risk benefit	0.0046	0.0043
Market risk benefits asset \| Minimum \| Discounted Cash Flow \| Mortality Multiplier
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market risk benefit	0.7500	0.8000
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 \| Surrender Rates
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market risk benefit	0.3000	0.3000
Market risk benefits asset \| Maximum \| Discounted Cash Flow \| Partial Withdrawal Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market risk benefit	0.2703	0.2564
Market risk benefits asset \| Maximum \| Discounted Cash Flow \| Non-Performance Spread
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market risk benefit	0.0095	0.0085
Market risk benefits asset \| Maximum \| Discounted Cash Flow \| Mortality Multiplier
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market risk benefit	1.2000	1.1500
Market risk benefits asset \| Maximum \| Discounted Cash Flow \| GMWB Utilization
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market risk benefit	0.7500	0.7500
Market risk benefits asset \| Weighted Average \| Discounted Cash Flow \| Surrender Rates
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market risk benefit	0.0619	0.0533
Market risk benefits asset \| Weighted Average \| Discounted Cash Flow \| Partial Withdrawal Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market risk benefit	0.0247	0.0247
Market risk benefits asset \| Weighted Average \| Discounted Cash Flow \| Non-Performance Spread
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market risk benefit	0.0079	0.0064
Market risk benefits asset \| Weighted Average \| Discounted Cash Flow \| Mortality Multiplier
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market risk benefit	0.9750	1.0000
Market risk benefits asset \| Weighted Average \| Discounted Cash Flow \| GMWB Utilization
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market risk benefit	0.6363	0.6303
Market risk benefits liability \| Discounted Cash Flow
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Liabilities, fair value	$ 906	$ 903
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 Withdrawal Rate
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	0.0046	0.0043
Market risk benefits liability \| Minimum \| Discounted Cash Flow \| Mortality Multiplier
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market risk benefit	0.7500	0.8000
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 \| Surrender Rates
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market risk benefit	0.3000	0.3000
Market risk benefits liability \| Maximum \| Discounted Cash Flow \| Partial Withdrawal Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market risk benefit	0.2703	0.2564
Market risk benefits liability \| Maximum \| Discounted Cash Flow \| Non-Performance Spread
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market risk benefit	0.0095	0.0085
Market risk benefits liability \| Maximum \| Discounted Cash Flow \| Mortality Multiplier
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market risk benefit	1.2000	1.1500
Market risk benefits liability \| Maximum \| Discounted Cash Flow \| GMWB Utilization
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market risk benefit	0.7500	0.7500
Market risk benefits liability \| Weighted Average \| Discounted Cash Flow \| Surrender Rates
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market risk benefit	0.0619	0.0533
Market risk benefits liability \| Weighted Average \| Discounted Cash Flow \| Partial Withdrawal Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market risk benefit	0.0247	0.0247
Market risk benefits liability \| Weighted Average \| Discounted Cash Flow \| Non-Performance Spread
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market risk benefit	0.0079	0.0064
Market risk benefits liability \| Weighted Average \| Discounted Cash Flow \| Mortality Multiplier
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market risk benefit	0.9750	1.0000
Market risk benefits liability \| Weighted Average \| Discounted Cash Flow \| GMWB Utilization
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market risk benefit	0.6363	0.6303

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