INVESTMENTS (Reverse Repurchase Agreements) (Details) - USD ($)	Jun. 30, 2020	Dec. 31, 2019
Investments, Debt and Equity Securities [Abstract]
Value of reverse repurchase agreements	$ 249,000,000	$ 0
Minimum required collateral for reverse repurchase agreements, expressed as a percentage of loan principal	102.00%

Minimum value of securities received as collateral against securities purchased under agreement to resell, expressed as a percentage of loan principal.

No definition available.

Name:	axs_SecuritiesPurchasedUnderAgreementsToResellRequiredCollateralPercentageOfPrincipal
Namespace Prefix:	axs_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant