DERIVATIVE INSTRUMENTS (DETAILS 4) (USD $) In Millions, unless otherwise specified	Dec. 31, 2009
DERIVATIVE INSTRUMENTS [Abstract]
Face value of asset back note collateralized by a portfolio of life settlement contracts	$ 400
Term (in years) of asset back note collateralized by a portfolio of life settlement contracts	10

Face value of an insured asset-backed note collateralized by a portfolio of life settlement contracts and cash.

No definition available.

Name:	axs_InsuredAssetBackedSecurityCollateralizedByLifeSettlementContractsFaceValue
Namespace Prefix:	axs_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant