XML 99 R83.htm IDEA: XBRL DOCUMENT
v3.21.1

Derivative Contracts - Additional Information (Details) - USD ($) $ in Millions | 12 Months Ended |  |
--- | --- | --- | ---
Dec. 31, 2020 | Dec. 31, 2019 | Sep. 30, 2019 | Mar. 31, 2019
Foreign exchange contracts | Not Designated as Hedging Instrument |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |
Purchase of US and foreign exchange | $ 1,402.3 | $ 1,696.3 |  |
Collateral provided to counterparties as security for the Company's net liability position | 3.4 | 2.9 |  |
Foreign exchange contracts | Not Designated as Hedging Instrument | Derivative At Fair Value |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |
Purchase of US and foreign exchange | 803.1 | 687.3 |  |
Foreign exchange contracts | Not Designated as Hedging Instrument | Liabilities Under Derivative Contracts |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |
Purchase of US and foreign exchange | 599.2 | 1,009.0 |  |
Foreign exchange contracts | Designated as Hedging Instrument | Derivative At Fair Value |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |
Purchase of US and foreign exchange | 90.6 | 85.5 |  |
Foreign exchange contracts | Net change from current period hedged transactions | Designated as Hedging Instrument |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |
Gain (loss) on foreign currency fair value hedge derivatives | 0.3 | 4.8 |  |
Foreign exchange contracts | General, administrative and corporate expenses | Designated as Hedging Instrument |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |
Gain (loss) on foreign currency fair value hedge derivatives | (3.2) | 0.9 |  |
Foreign exchange contracts | Gain (loss) on derivative instruments | Not Designated as Hedging Instrument |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |
Gain (loss) to net income from derivative instruments | 16.0 | (14.0) |  |
Interest rate swap | Not Designated as Hedging Instrument |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |
Initial and variation margin, posted | 0.0 | 111.1 |  |
Interest rate swap | Not Designated as Hedging Instrument | Liabilities Under Derivative Contracts |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |
Purchase of US and foreign exchange | 0.0 | 1,800.0 | $ 1,800.0 | $ 3,138.0
Interest rate swap | Gain (loss) on derivative instruments | Not Designated as Hedging Instrument |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |
Gain (loss) to net income from derivative instruments | $ (81.1) | $ (130.2) |  |

X
- Definition Margin Already Posted, Aggregate Fair Value + References No definition available. + Details
Name: | ahl_MarginAlreadyPostedAggregateFairValue
Namespace Prefix: | ahl_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The aggregate fair value of assets that are already posted, at the end of the reporting period, as collateral for derivative instruments with credit-risk-related contingent features. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4H -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5624258-113959 + Details
Name: | us-gaap_CollateralAlreadyPostedAggregateFairValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- 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 No definition available. + Details
Name: | us-gaap_DerivativeInstrumentsGainLossLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of realized and unrealized gain (loss) of derivative instruments not designated or qualifying as hedging instruments. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4CC -URI http://asc.fasb.org/extlink&oid=109980867&loc=SL109998890-113959 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4C -Subparagraph (e) -URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5624171-113959 + Details
Name: | us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Nominal or face amount used to calculate payment on derivative. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 1B -URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5580258-113959 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 1A -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5579245-113959 + Details
Name: | us-gaap_DerivativeNotionalAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount of gain (loss) from the increase (decrease) in fair value of foreign currency derivatives and nonderivative instruments designated as fair value hedging instruments which were recognized in earnings, net of offsets by the gain (loss) on the hedged item to the extent that the fair value hedge was determined to be effective. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4C -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5624171-113959 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4A -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5618551-113959 + Details
Name: | us-gaap_GainLossOnForeignCurrencyFairValueHedgeDerivatives
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=us-gaap_ForeignExchangeContractMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_HedgingDesignationAxis=us-gaap_NondesignatedMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_BalanceSheetLocationAxis=ahl_DerivativeAtFairValueMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_BalanceSheetLocationAxis=ahl_LiabilitiesUnderDerivativeContractsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_HedgingDesignationAxis=us-gaap_DesignatedAsHedgingInstrumentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeStatementLocationAxis=ahl_NetchangefromcurrentperiodhedgedtransactionsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeStatementLocationAxis=us-gaap_GeneralAndAdministrativeExpenseMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeStatementLocationAxis=us-gaap_GainLossOnDerivativeInstrumentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=us-gaap_InterestRateSwapMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |