XML 134 R113.htm IDEA: XBRL DOCUMENT v3.25.1

Commitments and Contingencies - Additional Information (Details) £ in Millions, SFr in Millions, $ in Millions, $ in Millions, $ in Millions, $ in Millions		12 Months Ended
		Dec. 31, 2024 USD ($) Investment	Dec. 31, 2023 USD ($) Investment	Dec. 31, 2022 USD ($)	Dec. 31, 2024 GBP (£) Investment	Dec. 31, 2024 CAD ($) Investment	Dec. 31, 2024 AUD ($) Investment	Dec. 31, 2024 CHF (SFr) Investment	Dec. 31, 2024 SGD ($) Investment	Dec. 31, 2023 GBP (£) Investment	Dec. 31, 2023 CAD ($) Investment	Dec. 31, 2023 AUD ($) Investment	Dec. 31, 2023 CHF (SFr) Investment	Dec. 31, 2023 SGD ($) Investment	Sep. 30, 2021 USD ($)	Dec. 20, 2017 USD ($)
Restricted Cash And Collateral [Line Items]
Other investments (equity method)	[1]	$ 267.2	$ 209.3
Total as percent of invested assets		46.40%	50.20%
Investable assets held by the Company		$ 7,700.0	$ 7,500.0
Commitment to invest in private assets		57.0	99.0	$ 377.9
Investable assets held by insurance regulators		$ 471.9	517.4
Minimum capital required | £					£ 0.4					£ 0.5
Percentage of reinsurance liabilities		100.00%			100.00%	100.00%	100.00%	100.00%	100.00%
Reinsurance liabilities		$ 648.8	823.5
Assets held-in-trust		1,001.5	1,016.9
Regulatory deposits		6.9	6.8
Deposit with states		$ 6.5	$ 6.4
Number of investments | Investment		1	1		1	1	1	1	1	1	1	1	1	1
Us Multi Beneficiary Trust Fund
Restricted Cash And Collateral [Line Items]
Minimum trust fund		$ 20.0
Assets held-in-trust		334.0	$ 394.7
US Surplus Lines Trust Fund
Restricted Cash And Collateral [Line Items]
Assets held-in-trust		150.2	126.6
Canadian Trust Fund
Restricted Cash And Collateral [Line Items]
Assets held-in-trust		162.7				$ 219.8					$ 228.4
Australian Trust Fund
Restricted Cash And Collateral [Line Items]
Assets held-in-trust		54.1					$ 78.1					$ 131.0
Swiss Trust Fund
Restricted Cash And Collateral [Line Items]
Assets held-in-trust		5.7						SFr 4.8					SFr 9.9
Singapore Trust Fund
Restricted Cash And Collateral [Line Items]
Assets held-in-trust		$ 157.3							$ 201.7					$ 192.1
Bermuda
Restricted Cash And Collateral [Line Items]
Percentage of reinsurance liabilities		100.00%			100.00%	100.00%	100.00%	100.00%	100.00%
Reinsurance liabilities		$ 182.3	$ 320.6
Limited Partner
Restricted Cash And Collateral [Line Items]
Restricted assets															$ 20.0	$ 100.0
[1] Other investments includes related party investments in Funds Managed by Apollo of $78.6 million (2023 — $39.8 million).

X

- Definition

Collateral funds held as percentage of cash and short term investments

+ References

No definition available.

+ Details

Name:	ahl_CollateralFundsHeldAsPercentageOfCashAndShortTermInvestments
Namespace Prefix:	ahl_
Data Type:	dtr-types1:percentItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Deposit with states

+ References

No definition available.

+ Details

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

X

- Definition

Minimum trust fund

+ References

No definition available.

+ Details

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

X

- Definition

Number Of Investments In Variable Interest Entities

+ References

No definition available.

+ Details

Name:	ahl_NumberOfInvestmentsInVariableInterestEntities
Namespace Prefix:	ahl_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Payments to Acquire Privately-held Investments, Trading

+ References

No definition available.

+ Details

Name:	ahl_PaymentsToAcquirePrivatelyHeldInvestmentsTrading
Namespace Prefix:	ahl_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

Percentage of reinsurance liabilities

+ References

No definition available.

+ Details

Name:	ahl_PercentageOfReinsuranceLiabilities
Namespace Prefix:	ahl_
Data Type:	dtr-types1:percentItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Regulatory deposits

+ References

No definition available.

+ Details

Name:	ahl_RegulatoryDeposits
Namespace Prefix:	ahl_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

Reinsurance Liabilities

+ References

No definition available.

+ Details

Name:	ahl_ReinsuranceLiabilities
Namespace Prefix:	ahl_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

Restricted assets

+ References

No definition available.

+ Details

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

X

- Definition

Restricted Cash And Collateral

+ References

No definition available.

+ Details

Name:	ahl_RestrictedCashAndCollateralLineItems
Namespace Prefix:	ahl_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Minimum amount of net capital required to be maintained by broker-dealer and its subsidiary, calculated under Aggregate Indebtedness Standard.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name Rule 15c3-1
-Number 240
-Section 15c3-1
-Publisher SEC

+ Details

Name:	srt_MinimumNetCapitalRequired1
Namespace Prefix:	srt_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

Carrying amount of cash and investment securities on deposit with state regulatory authorities in connection with capital requirements.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 825
-Name Accounting Standards Codification
-Section 50
-Paragraph 1A
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477351/944-825-50-1A

+ Details

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

X

- Definition

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.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(b))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480678/235-10-S99-1

+ Details

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

X

- Definition

Cash includes currency on hand as well as demand deposits with banks or financial institutions. It also includes other kinds of accounts that have the general characteristics of demand deposits in that the customer may deposit additional funds at any time and effectively may withdraw funds at any time without prior notice or penalty. Cash equivalents, excluding items classified as marketable securities, include short-term, highly liquid Investments that are both readily convertible to known amounts of cash, and so near their maturity that they present minimal risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three years ago does not become a cash equivalent when its remaining maturity is three months. Short-term investments, exclusive of cash equivalents, generally consist of marketable securities intended to be sold within one year (or the normal operating cycle if longer) and may include trading securities, available-for-sale securities, or held-to-maturity securities (if maturing within one year), as applicable.

+ 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(9))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

+ Details

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

X

- 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

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(3)(a))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478777/944-210-S99-1

+ Details

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

X

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=ahl_UsMultiBeneficiaryTrustFundMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=ahl_USSurplusLinesTrustFundMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=ahl_CanadianTrustFundMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=ahl_AustralianTrustFundMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=ahl_SwissTrustFundMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=ahl_SingaporeTrustFundMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	dei_LegalEntityAxis=ahl_AspenBermudaMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

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