XML 33 R79.htm IDEA: XBRL DOCUMENT v3.20.1

Reinsurance - Additional Information (Details) $ in Millions	12 Months Ended
	Dec. 31, 2017 USD ($)
Reinsurance Disclosures [Abstract]
Liability for unpaid claims and claims adjustment expense amount ceded	$ (125.5)

X

- Definition

Liability For Unpaid Claims And Claims Adjustment Expense Amount Disposed of or Ceded

+ References

No definition available.

+ Details

Name:	ahl_LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseAmountDisposedoforCeded
Namespace Prefix:	ahl_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- References

No definition available.

+ Details

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