Face (par) amount of debt instrument at time of issuance.

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+ Details

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

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Date the debt instrument was issued, in CCYY-MM-DD format.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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Balance Type:	na
Period Type:	duration

- Definition

Aggregate amount of interest paid or due on all long-term debt.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 220
-Section S99
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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

No definition available.

+ Details

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

- Definition

Maturity date of long-term debt, in CCYY-MM-DD format.

+ References

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-Publisher FASB
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-Topic 820
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Period Type:	instant

- Details

Name:	us-gaap_DebtInstrumentAxis=ahl_SeniorNotesDue2028Member
Namespace Prefix:
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Balance Type:
Period Type:

- Details

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Balance Type:
Period Type:

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Name:	us-gaap_DebtInstrumentAxis=ahl_SeniorNotesDue2031Member
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Period Type:

Debt - Senior Note Issuance (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Line of Credit Facility [Line Items]
Interest Expense, Long-term Debt	$ 69	$ 42	$ 41
Senior Notes due 2028
Line of Credit Facility [Line Items]
Debt Instrument, Issuance Date	Jan. 12, 2018
Debt Instrument, Face Amount	$ 1,000	$ 1,000
Interest rate	4.125%	4.125%
Long-term Debt, Maturity Date	Jan. 12, 2028
Senior Notes due 2030
Line of Credit Facility [Line Items]
Debt Instrument, Issuance Date	Apr. 03, 2020
Debt Instrument, Face Amount	$ 500
Interest rate	6.15%
Long-term Debt, Maturity Date	Apr. 03, 2030
Senior Notes due 2031
Line of Credit Facility [Line Items]
Debt Instrument, Issuance Date	Oct. 08, 2020
Debt Instrument, Face Amount	$ 500
Interest rate	3.50%
Long-term Debt, Maturity Date	Jan. 15, 2031