Alternative investments as a percentage of overall invested assets.

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Amortized cost of portfolio rated below investment grade.

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This item represents the change in gross unrealized holding gain or loss on available-for-sale securities that has been included in accumulated other comprehensive income, a separate component of shareholders' equity, during the period.

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Percentage of the fair value of portfolio that was rated investment grade as of balance sheet date.

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This item represents the percentage of the fair value of securities obtained as collateral under reverse repurchase agreements

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Fair value of portfolio rated below investment grade.

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Financing Receivable, Number Of Loans In Foreclosure

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Financing Receivable, Number Of Loans Past Due

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Gain (Loss) On Modification Of Financing Receivable

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This item represents total investment commitments as of the balance sheet date for fixed maturity available-for-sale securities, limited partnerships, real estate and mortgage loans on real estate.

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This item represents investment commitments as of the balance sheet date for limited partnerships.

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This item represents investment commitments as of the balance sheet date for private placements.

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This item represents investment commitments as of the balance sheet date for mortgage loans.

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Investments

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Number of partnerships represented in alternative investment portfolio.

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- Definition

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

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Amount excluding accrued interest, of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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This item represents disclosure of all significant concentrations of credit risk or market risk arising from the subject financial instrument (as defined), whether from an individual counterparty or groups of counterparties.

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Fair value of collateral permitted, by contact or custom, to be sold or re-pledged.

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Fair value of the collateral, or portion thereof, that has been re-pledged, delivered, or otherwise used.

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- Definition

Recorded investment of consumer mortgage loan receivables secured by residential real estate properties for which formal foreclosure proceedings are in process.

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Investments - Narrative (Details)	3 Months Ended		12 Months Ended
Investments - Narrative (Details)	Mar. 31, 2024 USD ($) loan investment	Mar. 31, 2023 USD ($)	Dec. 31, 2023 USD ($) investment loan
Investments [Line Items]
Decrease in gross AFS securities unrealized gains (losses)	$ (669,000,000)
Losses from loan modifications	$ 0	$ 0
Number of partnerships in alternative investment portfolio \| investment	338		332
Alternative investments as a percentage of overall invested assets	3.00%		3.00%
Fair value of collateral received that we are permitted to sell or re-pledge	$ 25,000,000
Fixed maturity available-for-sale securities, at fair value	81,880,000,000		$ 82,300,000,000
Investment commitments	3,800,000,000
Investment commitments for limited partnerships	2,800,000,000
Investment commitments for mortgage loans on real estate	748,000,000
Investment commitments for private placements	192,000,000
Asset Pledged as Collateral
Investments [Line Items]
Fixed maturity available-for-sale securities, at fair value	52,000,000
Derivative Counterparties
Investments [Line Items]
Fair value of collateral received that we are permitted to sell or re-pledge	1,700,000,000
Fair value of securities received as collateral that have been resold or repledged	$ 527,000,000
Minimum
Investments [Line Items]
Percentage of the fair value of securities obtained as collateral under reverse repurchase agreements.	80.00%
Maximum
Investments [Line Items]
Percentage of the fair value of securities obtained as collateral under reverse repurchase agreements.	95.00%
Residential
Investments [Line Items]
Number of loans past due \| loan	118		116
Number of loans in foreclosure \| loan	82		82
Mortgage loans in process of foreclosure, amount	$ 35,000,000		$ 38,000,000
California \| Mortgages \| Geographic Concentration Risk \| Commercial
Investments [Line Items]
Concentration risk	26.00%		27.00%
California \| Mortgages \| Geographic Concentration Risk \| Residential
Investments [Line Items]
Concentration risk	14.00%		14.00%
Texas \| Mortgages \| Geographic Concentration Risk \| Commercial
Investments [Line Items]
Concentration risk	10.00%		9.00%
New York \| Mortgages \| Geographic Concentration Risk \| Residential
Investments [Line Items]
Concentration risk	12.00%		12.00%
Corporate bonds
Investments [Line Items]
Amortized cost of portfolio rated below investment grade	$ 2,600,000,000		$ 2,700,000,000
Fair value of portfolio rated below investment grade	$ 2,500,000,000		$ 2,600,000,000
Corporate bonds \| Credit Assessment \| Reinsurer Concentration Risk
Investments [Line Items]
Percentage of fair value rated as investment grade	96.00%		96.00%
White Chapel V LLC \| MBS
Investments [Line Items]
Fair value, concentration of risk	$ 1,500,000,000		$ 1,300,000,000
White Chapel V LLC \| Investments \| Lender Concentration Risk \| MBS
Investments [Line Items]
Concentration risk	1.00%		1.00%
White Chapel LLC \| MBS
Investments [Line Items]
Fair value, concentration of risk	$ 1,100,000,000		$ 1,000,000,000
White Chapel LLC \| Investments \| Lender Concentration Risk \| MBS
Investments [Line Items]
Concentration risk	1.00%		1.00%
Financial Service \| Securities Investment
Investments [Line Items]
Fair value, concentration of risk	$ 16,400,000,000		$ 16,600,000,000
Financial Service \| Investments \| Lender Concentration Risk \| Securities Investment
Investments [Line Items]
Concentration risk	14.00%		14.00%
Consumer Non-Cyclical Industry \| Securities Investment
Investments [Line Items]
Fair value, concentration of risk	$ 11,200,000,000		$ 11,300,000,000
Consumer Non-Cyclical Industry \| Investments \| Lender Concentration Risk \| Securities Investment
Investments [Line Items]
Concentration risk	9.00%		10.00%