Catastrophe Bond

No definition available.

Name:	ahl_CatastropheBond
Namespace Prefix:	ahl_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Investment Funds

+ References

No definition available.

+ Details

Name:	ahl_InvestmentFunds
Namespace Prefix:	ahl_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Restricted assets.

+ References

No definition available.

+ Details

Name:	ahl_RestrictedAssets
Namespace Prefix:	ahl_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount 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).

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 326
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 9
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479106/326-30-50-9

+ Details

Name:	us-gaap_DebtSecuritiesAvailableForSaleAllowanceForCreditLossPeriodIncreaseDecrease
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of accumulated unrealized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in unrealized loss position, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Subparagraph (a)(2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-6

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Subparagraph (a)(2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479106/326-30-50-4

+ Details

Name:	us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Number of investments in debt securities measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in unrealized loss position, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Subparagraph (b)(3)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-6

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Subparagraph (b)(3)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479106/326-30-50-4

+ Details

Name:	us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionNumberOfPositions
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

This element represents the aggregate cost of investments accounted for under the equity method of accounting.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.12)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1

+ Details

Name:	us-gaap_EquityMethodInvestmentAggregateCost
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 323
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481687/323-10-50-3

+ Details

Name:	us-gaap_EquityMethodInvestmentOwnershipPercentage
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of income (loss) for proportionate share of equity method investee's income (loss).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 45
-Paragraph 28
-Subparagraph (b)
-SubTopic 10
-Topic 230
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482740/230-10-45-28

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(10))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483586/944-220-S99-1

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 323
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481664/323-10-45-1

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 22
-Subparagraph (g)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-22

Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(12))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483621/220-10-S99-2

Reference 6: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 942
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04(13)(f))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483589/942-220-S99-1

+ Details

Name:	us-gaap_IncomeLossFromEquityMethodInvestments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- 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.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482106/820-10-50-2

+ Details

Name:	us-gaap_InvestmentsFairValueDisclosure
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Minimum amount of other commitment not otherwise specified in the taxonomy. Excludes commitments explicitly modeled in the taxonomy, including but not limited to, long-term and short-term purchase commitments, recorded and unrecorded purchase obligations, supply commitments, registration payment arrangements, leases, debt, product warranties, guarantees, environmental remediation obligations, and pensions.

+ References

No definition available.

+ Details

Name:	us-gaap_OtherCommitment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of investments classified as other.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(12))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1

+ Details

Name:	us-gaap_OtherInvestments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The net cash outflow or inflow associated with the acquisition or sale of a business segment during the period.

+ References

No definition available.

+ Details

Name:	us-gaap_PaymentsForProceedsFromBusinessesAndInterestInAffiliates
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The cash inflow associated with the sale of equity method investments, which are investments in joint ventures and entities in which the entity has an equity ownership interest normally of 20 to 50 percent and exercises significant influence.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482740/230-10-45-12

+ Details

Name:	us-gaap_ProceedsFromSaleOfEquityMethodInvestments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

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.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(7)(c))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483621/220-10-S99-2

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(9)(a))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483621/220-10-S99-2

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 9
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-9

+ Details

Name:	us-gaap_ScheduleOfGainLossOnInvestmentsIncludingMarketableSecuritiesAndInvestmentsHeldAtCostIncomeStatementReportedAmountsSummaryLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of investment in debt security measured at fair value with change in fair value recognized in net income (trading) and investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(2))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483467/210-10-45-1

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.4)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479853/942-210-S99-1

+ Details

Name:	us-gaap_TradingSecurities
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

Name:	us-gaap_ExternalCreditRatingByGroupingAxis=us-gaap_ExternalCreditRatingNonInvestmentGradeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_InvestmentIdentifierAxis=Unfunded Commitment, Apollo Real Estate Fund
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_InvestmentIdentifierAxis=Unfunded Commitment, Infrastructure fund
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_InvestmentIdentifierAxis=Unfunded Commitment, Managed Debt Fund
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_InvestmentIdentifierAxis=Unfunded Commitment, Managed lending fund
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_InvestmentIdentifierAxis=Unfunded Commitment, Real Estate Fund (Sept 2021)
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByMeasurementFrequencyAxis=us-gaap_FairValueMeasurementsRecurringMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=ahl_ApolloRealEstateFundMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_InvestmentTypeAxis=us-gaap_RealEstateFundsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_InvestmentTypeAxis=us-gaap_CommercialMortgageBackedSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_InvestmentTypeAxis=ahl_MiddlemarketloansMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_InvestmentTypeAxis=ahl_PrivatelyheldinvestmentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_InvestmentTypeAxis=ahl_RealEstateFundSept2021Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_InvestmentTypeAxis=ahl_InfrastructureFundMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_InvestmentTypeAxis=ahl_ManagedLendingFundDec2020Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_InvestmentTypeAxis=ahl_PledgeAccountsCustodianBankApril2021Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_InvestmentTypeAxis=ahl_ManagedDebtFundMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=ahl_MVIMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=ahl_DigitalRiskMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=ahl_MultiLineReinsurerMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PartnerTypeOfPartnersCapitalAccountAxis=us-gaap_LimitedPartnerMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_InvestmentTypeAxis=ahl_ManagedLendingFundMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Investments - Additional Information (Narrative) (Details)	1 Months Ended	12 Months Ended
	Mar. 31, 2021 USD ($)	Dec. 31, 2023 USD ($) security	Dec. 31, 2022 USD ($) security	Dec. 31, 2021 USD ($)	Aug. 31, 2023 USD ($)	Apr. 01, 2023 USD ($)	May 05, 2022 USD ($)	Apr. 01, 2022 USD ($)	Sep. 30, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 23, 2019 USD ($)	Dec. 20, 2017 USD ($)	Jan. 01, 2017 USD ($)
Gain (Loss) on Securities [Line Items]
Catastrophe bonds, trading, cost		$ 1,600,000	$ 2,900,000
Investment in the period		400,000	2,000,000.0
Equity method investment, aggregate cost		7,600,000	6,200,000	$ 3,900,000
Other investments, at fair value (2)		209,300,000	221,300,000
Investment in Multiline reinsurer		0	0
Investment funded		0
Available-for-sale investment, allowance for credit loss, increase (decrease)		$ (3,600,000)	$ 200,000
Number of Securities \| security		950	1,166
Available-for-sale securities, unrealized loss position		$ 221,800,000	$ 339,000,000.0
External Credit Rating, Non Investment Grade
Gain (Loss) on Securities [Line Items]
Available-for-sale securities, unrealized loss position		1,200,000
Investment, Identifier [Axis]: Unfunded Commitment, Apollo Real Estate Fund
Gain (Loss) on Securities [Line Items]
Unfunded commitment		4,100,000
Investment, Identifier [Axis]: Unfunded Commitment, Infrastructure fund
Gain (Loss) on Securities [Line Items]
Unfunded commitment		4,000,000
Investment, Identifier [Axis]: Unfunded Commitment, Managed Debt Fund
Gain (Loss) on Securities [Line Items]
Unfunded commitment		6,900,000
Investment, Identifier [Axis]: Unfunded Commitment, Managed lending fund
Gain (Loss) on Securities [Line Items]
Unfunded commitment		1,100,000
Investment, Identifier [Axis]: Unfunded Commitment, Real Estate Fund (Sept 2021)
Gain (Loss) on Securities [Line Items]
Unfunded commitment		2,200,000
Fair Value, Recurring [Member]
Gain (Loss) on Securities [Line Items]
Investments, fair value		117,100,000	134,600,000
Fair Value, Recurring [Member] \| Apollo real estate fund
Gain (Loss) on Securities [Line Items]
Other investments, at fair value (2)		23,900,000	25,300,000
Real estate fund \| Fair Value, Recurring [Member]
Gain (Loss) on Securities [Line Items]
Investments, fair value		209,300,000	221,300,000
Commercial mortgage loans
Gain (Loss) on Securities [Line Items]
Fair market value, trading		274,900,000	312,100,000
Middle market loans
Gain (Loss) on Securities [Line Items]
Fair market value, trading		84,800,000	106,900,000
Privately-held investments
Gain (Loss) on Securities [Line Items]
Fair market value, trading		475,000,000.0	533,000,000.0
Real estate fund (Sept 2021) \| Fair Value, Recurring [Member]
Gain (Loss) on Securities [Line Items]
Investments, fair value		39,800,000	40,600,000
Infrastructure fund \| Fair Value, Recurring [Member]
Gain (Loss) on Securities [Line Items]
Investments, fair value		10,800,000	8,200,000
Managed Lending Fund (Dec 2020) \| Fair Value, Recurring [Member]
Gain (Loss) on Securities [Line Items]
Investments, fair value		15,900,000	12,700,000
Pledge Accounts, Custodian Bank (April 2021) \| Fair Value, Recurring [Member]
Gain (Loss) on Securities [Line Items]
Investments, fair value		1,700,000	1,300,000
Managed debt fund \| Fair Value, Recurring [Member]
Gain (Loss) on Securities [Line Items]
Investments, fair value		100,000	0
MVI
Gain (Loss) on Securities [Line Items]
Investment in the period	$ 800,000	0	400,000
Equity method investment, aggregate cost		1,000,000.0	800,000	500,000
Gross realized and unrealized gains (loss)		200,000	0	100,000
Investment in Multiline reinsurer		0	0
Digital Re
Gain (Loss) on Securities [Line Items]
Investment in the period		0	0
Equity method investment, ownership percentage													49.00%
Equity method investment, aggregate cost		200,000	200,000	200,000									$ 2,300,000
Investment in Multiline reinsurer		0	0
Multi-Line Insurer
Gain (Loss) on Securities [Line Items]
Investment in the period		400,000	1,600,000
Equity method investment, aggregate cost		6,400,000	5,200,000	3,200,000
Other investments, at fair value (2)											$ 5,000,000
Gross realized and unrealized gains (loss)		800,000	(400,000)	$ 200,000
Investment in Multiline reinsurer		$ 0	$ 0
Limited Partner
Gain (Loss) on Securities [Line Items]
Restricted assets								$ 10,000,000	$ 20,000,000			$ 100,000,000
Limited Partner \| Real estate fund \| Apollo real estate fund
Gain (Loss) on Securities [Line Items]
Restricted assets								$ 30,000,000
Limited Partner \| Infrastructure fund
Gain (Loss) on Securities [Line Items]
Restricted assets							$ 15,000,000
Limited Partner \| Managed lending fund
Gain (Loss) on Securities [Line Items]
Restricted assets						$ 2,800,000				$ 10,500,000
Limited Partner \| Managed debt fund
Gain (Loss) on Securities [Line Items]
Restricted assets					$ 7,000,000