Represents the number of securities which had unrealized losses greater than 10% of book value for 12 months or more.

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This item represents the excess of amortized cost basis over fair value of securities that have been in a loss position for twelve months or longer for those securities which are categorized neither as held-to-maturity nor trading securities and which have unrealized losses greater than 10% of book value.

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Discontinued Operation, Continuing Involvement, Investment Management Commitment

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Investments, Authorized Amount To Invest

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Investments, Including Distributed Gains, Authorized Amount To Invest

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Number of Outside Managers Managing Investment Portfolio

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Interest, dividends, rents, ancillary and other revenues earned but not yet received by the entity on its investments.

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The total amount of cash and securities held by third party trustees pursuant to terms of debt instruments or other agreements as of the date of each statement of financial position presented, which can be used by the trustee only to pay the noncurrent portion of specified obligations.

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Amount, excluding accrued interest, of increase (decrease) in allowance for credit loss 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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- Definition

Fair value portion of investment securities, including, but not limited to, marketable securities, derivative financial instruments, and investments accounted for under the equity method.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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The minimum amount the entity agreed to spend under the long-term purchase commitment.

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Minimum amount to be expended to satisfy the terms of arrangements in which the entity has agreed to expend funds to procure goods or services, excluding long-term purchase commitments or unconditional purchase obligations.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Investments - Additional Information (Details) $ in Millions		3 Months Ended
	Apr. 05, 2023 USD ($)	Mar. 31, 2023 USD ($) manager Security	Mar. 31, 2022 USD ($)	Dec. 31, 2022 USD ($) Security
Schedule of Investments [Line Items]
Number of outside managers managing investment portfolio \| manager		3
Accrued investment income		$ 76		$ 71
Number of securities with unrealized losses greater than 10% of book value for 12 months or more \| Security		482		567
Total unrealized losses for securities having losses greater than 10% of book value for 12 months or more		$ 253		$ 329
Assets held-in-trust		229		222
Allowance for credit loss		(5)	$ (5)
Disposal Group, Held-for-sale, Not Discontinued Operations \| Sound Point Agreement
Schedule of Investments [Line Items]
Transaction commitment, new and transitioned investments		393
Subsequent Event \| Disposal Group, Held-for-sale, Not Discontinued Operations \| Sound Point Agreement
Schedule of Investments [Line Items]
Transaction commitment, new and transitioned investments	$ 1,000
PCD Accounting Model to PCI Securities
Schedule of Investments [Line Items]
Allowance for credit loss		4	$ 5
AGL Subsidiaries
Schedule of Investments [Line Items]
Assets held-in-trust		1,146		1,169
Future Equity Investments
Schedule of Investments [Line Items]
Remaining minimum amount committed		79
Future Equity Investments \| AGL Subsidiaries \| AssuredIM managed fixed-maturity securities
Schedule of Investments [Line Items]
Investments, including distributed gains, authorized amount to invest		853
Investments, authorized amount to invest		750
Invested Capital \| AGL Subsidiaries \| AssuredIM managed fixed-maturity securities
Schedule of Investments [Line Items]
Long-term purchase commitment, amount		366
Unfunded Commitment \| AGL Subsidiaries \| AssuredIM managed fixed-maturity securities
Schedule of Investments [Line Items]
Long-term purchase commitment, amount		247
Equity in Earnings (Losses) of Investees \| AGL Subsidiaries \| AssuredIM managed fixed-maturity securities
Schedule of Investments [Line Items]
Long-term purchase commitment, amount		613
Equity in Earnings (Losses) of Investees \| AGAS \| AssuredIM managed fixed-maturity securities
Schedule of Investments [Line Items]
Investments, fair value disclosure		$ 396		$ 569