Fair Value of Assets and Liabilities Fair Value of Assets and Liabilities (Quantitative Information for Level 3 Inputs) (Details) $ in Millions	Mar. 31, 2025 USD ($)		Dec. 31, 2024 USD ($)
Fair Value, Option, Quantitative Disclosures [Line Items]
Assets, Fair Value Disclosure	$ 88,905	[1]	$ 80,121	[2]
Valuation, Income Approach [Member] | Other Liabilities
Fair Value, Option, Quantitative Disclosures [Line Items]
Financial and Nonfinancial Liabilities, Fair Value Disclosure	1		2
Corporate Debt Securities [Member] | Valuation, Market Approach [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Assets, Fair Value Disclosure	$ 352		$ 99
Corporate Debt Securities [Member] | Maximum [Member] | Valuation, Market Approach [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Debt Instrument, Measurement Input	0.02		0.02
Asset-backed Securities [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Assets, Fair Value Disclosure	$ 677		$ 564
Asset-backed Securities [Member] | Weighted Average [Member] | Valuation, Market Approach [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Debt Instrument, Measurement Input	0.05		0.03
Asset-backed Securities [Member] | Maximum [Member] | Valuation, Market Approach [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Debt Instrument, Measurement Input	0.20		0.10
Asset-backed Securities [Member] | Minimum [Member] | Valuation, Market Approach [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Debt Instrument, Measurement Input	0		0
US Government Agencies Debt Securities [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Assets, Fair Value Disclosure	$ 4		$ 0
US Government Agencies Debt Securities [Member] | Weighted Average [Member] | Valuation, Market Approach [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Debt Instrument, Measurement Input	0.01
US Government Agencies Debt Securities [Member] | Maximum [Member] | Valuation, Market Approach [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Debt Instrument, Measurement Input	0.01
US Government Agencies Debt Securities [Member] | Minimum [Member] | Valuation, Market Approach [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Debt Instrument, Measurement Input	0
Equity securities | Valuation, Market Approach [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Assets, Fair Value Disclosure	$ 31		$ 33
Equity securities | Weighted Average [Member] | Valuation, Market Approach [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Debt Instrument, Measurement Input	0.04		0.04
Funds Withheld At Interest Embedded Derivatives [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Assets, Fair Value Disclosure	$ 24		$ 22
Embedded Derivatives In Indexed Annuity [Member] | Valuation, Income Approach [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Financial and Nonfinancial Liabilities, Fair Value Disclosure	$ 383		$ 435
Embedded Derivatives In Indexed Annuity [Member] | Weighted Average [Member] | Valuation Technique, Discounted Cash Flow [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Embedded Derivative Liability, Measurement Input	0.02		0.02
Embedded Derivatives In Indexed Annuity [Member] | Maximum [Member] | Valuation Technique, Discounted Cash Flow [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Embedded Derivative Liability, Measurement Input	0.04		0.04
Embedded Derivatives In Indexed Annuity [Member] | Minimum [Member] | Valuation Technique, Discounted Cash Flow [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Embedded Derivative Liability, Measurement Input	0.01		0.01
Total Return Swap | Other Assets
Fair Value, Option, Quantitative Disclosures [Line Items]
Assets, Fair Value Disclosure	$ 1		$ 2
Measurement Input Crediting Rate [Member] | Funds Withheld At Interest Embedded Derivatives [Member] | Weighted Average [Member] | Valuation, Income Approach [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Embedded Derivative Asset, Measurement Input	0.02		0.02
Measurement Input Crediting Rate [Member] | Funds Withheld At Interest Embedded Derivatives [Member] | Maximum [Member] | Valuation, Income Approach [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Embedded Derivative Asset, Measurement Input	0.04		0.04
Measurement Input Crediting Rate [Member] | Funds Withheld At Interest Embedded Derivatives [Member] | Minimum [Member] | Valuation, Income Approach [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Embedded Derivative Asset, Measurement Input	0.01		0.01
Measurement Input, Counterparty Credit Risk [Member] | Funds Withheld At Interest Embedded Derivatives [Member] | Weighted Average [Member] | Valuation, Income Approach [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Embedded Derivative Asset, Measurement Input	0		0
Measurement Input, Counterparty Credit Risk [Member] | Funds Withheld At Interest Embedded Derivatives [Member] | Maximum [Member] | Valuation, Income Approach [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Embedded Derivative Asset, Measurement Input	0.05		0.05
Measurement Input, Counterparty Credit Risk [Member] | Funds Withheld At Interest Embedded Derivatives [Member] | Minimum [Member] | Valuation, Income Approach [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Embedded Derivative Asset, Measurement Input	0		0
Measurement Input, Withdrawal Rate [Member] | Funds Withheld At Interest Embedded Derivatives [Member] | Weighted Average [Member] | Valuation, Income Approach [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Embedded Derivative Asset, Measurement Input	0.05		0.04
Measurement Input, Withdrawal Rate [Member] | Funds Withheld At Interest Embedded Derivatives [Member] | Maximum [Member] | Valuation, Income Approach [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Embedded Derivative Asset, Measurement Input	0.10		0.10
Measurement Input, Withdrawal Rate [Member] | Funds Withheld At Interest Embedded Derivatives [Member] | Minimum [Member] | Valuation, Income Approach [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Embedded Derivative Asset, Measurement Input	0		0
Measurement Input, Withdrawal Rate [Member] | Embedded Derivatives In Indexed Annuity [Member] | Weighted Average [Member] | Valuation Technique, Discounted Cash Flow [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Embedded Derivative Liability, Measurement Input	0.04		0.04
Measurement Input, Withdrawal Rate [Member] | Embedded Derivatives In Indexed Annuity [Member] | Maximum [Member] | Valuation Technique, Discounted Cash Flow [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Embedded Derivative Liability, Measurement Input	0.10		0.10
Measurement Input, Withdrawal Rate [Member] | Embedded Derivatives In Indexed Annuity [Member] | Minimum [Member] | Valuation Technique, Discounted Cash Flow [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Embedded Derivative Liability, Measurement Input	0		0
Measurement Input, Lapse Rate [Member] | Funds Withheld At Interest Embedded Derivatives [Member] | Weighted Average [Member] | Valuation, Income Approach [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Embedded Derivative Asset, Measurement Input	0.18		0.18
Measurement Input, Lapse Rate [Member] | Funds Withheld At Interest Embedded Derivatives [Member] | Maximum [Member] | Valuation, Income Approach [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Embedded Derivative Asset, Measurement Input	0.35		0.35
Measurement Input, Lapse Rate [Member] | Funds Withheld At Interest Embedded Derivatives [Member] | Minimum [Member] | Valuation, Income Approach [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Embedded Derivative Asset, Measurement Input	0		0
Measurement Input, Lapse Rate [Member] | Embedded Derivatives In Indexed Annuity [Member] | Weighted Average [Member] | Valuation Technique, Discounted Cash Flow [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Embedded Derivative Liability, Measurement Input	0.17		0.17
Measurement Input, Lapse Rate [Member] | Embedded Derivatives In Indexed Annuity [Member] | Maximum [Member] | Valuation Technique, Discounted Cash Flow [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Embedded Derivative Liability, Measurement Input	0.35		0.35
Measurement Input, Lapse Rate [Member] | Embedded Derivatives In Indexed Annuity [Member] | Minimum [Member] | Valuation Technique, Discounted Cash Flow [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Embedded Derivative Liability, Measurement Input	0		0
Measurement Input, Mortality Rate [Member] | Funds Withheld At Interest Embedded Derivatives [Member] | Weighted Average [Member] | Valuation, Income Approach [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Embedded Derivative Asset, Measurement Input	0.04		0.03
Measurement Input, Mortality Rate [Member] | Funds Withheld At Interest Embedded Derivatives [Member] | Maximum [Member] | Valuation, Income Approach [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Embedded Derivative Asset, Measurement Input	1		1
Measurement Input, Mortality Rate [Member] | Funds Withheld At Interest Embedded Derivatives [Member] | Minimum [Member] | Valuation, Income Approach [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Embedded Derivative Asset, Measurement Input	0		0
Measurement Input, Mortality Rate [Member] | Embedded Derivatives In Indexed Annuity [Member] | Weighted Average [Member] | Valuation Technique, Discounted Cash Flow [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Embedded Derivative Liability, Measurement Input	0.03		0.03
Measurement Input, Mortality Rate [Member] | Embedded Derivatives In Indexed Annuity [Member] | Maximum [Member] | Valuation Technique, Discounted Cash Flow [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Embedded Derivative Liability, Measurement Input	1		1
Measurement Input, Mortality Rate [Member] | Embedded Derivatives In Indexed Annuity [Member] | Minimum [Member] | Valuation Technique, Discounted Cash Flow [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Embedded Derivative Liability, Measurement Input	0		0
Measurement Input, EBITDA Multiple [Member] | Corporate Debt Securities [Member] | Weighted Average [Member] | Valuation, Market Approach [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Debt Instrument, Measurement Input	9.3		11.0
Measurement Input, EBITDA Multiple [Member] | Corporate Debt Securities [Member] | Maximum [Member] | Valuation, Market Approach [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Debt Instrument, Measurement Input	11.0		9.7
Measurement Input, EBITDA Multiple [Member] | Corporate Debt Securities [Member] | Minimum [Member] | Valuation, Market Approach [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Debt Instrument, Measurement Input	6.2		6.7
Measurement Input, EBITDA Multiple [Member] | Equity securities | Weighted Average [Member] | Valuation, Market Approach [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Equity Securities, FV-NI, Measurement Input	10.5		10.9
Measurement Input, EBITDA Multiple [Member] | Equity securities | Maximum [Member] | Valuation, Market Approach [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Equity Securities, FV-NI, Measurement Input	11.8		12.8
Measurement Input, EBITDA Multiple [Member] | Equity securities | Minimum [Member] | Valuation, Market Approach [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Equity Securities, FV-NI, Measurement Input	7.4		7.4
Measurement Input, Credit Spread | Other Liabilities | Weighted Average [Member] | Valuation, Income Approach [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Derivative Liability, Measurement Input	0		0
Measurement Input, Credit Spread | Other Liabilities | Maximum [Member] | Valuation, Income Approach [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Derivative Liability, Measurement Input	0.01		0.01
Measurement Input, Credit Spread | Other Liabilities | Minimum [Member] | Valuation, Income Approach [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Derivative Liability, Measurement Input	0		0
Measurement Input, Credit Spread | Other Assets | Weighted Average [Member] | Valuation, Income Approach [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Derivative Asset, Measurement Input	0		0
Measurement Input, Credit Spread | Other Assets | Maximum [Member] | Valuation, Income Approach [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Derivative Asset, Measurement Input	0.01		0.01
Measurement Input, Credit Spread | Other Assets | Minimum [Member] | Valuation, Income Approach [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Derivative Asset, Measurement Input	0		0
Measurement Input, Default Rate | Other Liabilities | Weighted Average [Member] | Valuation, Income Approach [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Derivative Liability, Measurement Input	0		0
Measurement Input, Default Rate | Other Liabilities | Maximum [Member] | Valuation, Income Approach [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Derivative Liability, Measurement Input	0.07		0.08
Measurement Input, Default Rate | Other Liabilities | Minimum [Member] | Valuation, Income Approach [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Derivative Liability, Measurement Input	0		0
Measurement Input, Default Rate | Other Assets | Weighted Average [Member] | Valuation, Income Approach [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Derivative Asset, Measurement Input	0		0
Measurement Input, Default Rate | Other Assets | Maximum [Member] | Valuation, Income Approach [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Derivative Asset, Measurement Input	0.07		0.08
Measurement Input, Default Rate | Other Assets | Minimum [Member] | Valuation, Income Approach [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Derivative Asset, Measurement Input	0		0

[1] Excludes limited partnerships that are measured at estimated fair value using the NAV per share (or its equivalent) as a practical expedient. As of March 31, 2025, the fair value of such investments was $963 million.

[2] Excludes limited partnerships that are measured at estimated fair value using the NAV per share (or its equivalent) as a practical expedient. As of December 31, 2024, the fair value of such investments was $966 million