XML 49 R50.htm IDEA: XBRL DOCUMENT
v2.4.1.9

SEGMENT INFORMATION (DETAILS) (USD $) In Thousands, unless otherwise specified | 3 Months Ended | 12 Months Ended
--- | --- | ---
Dec. 31, 2014 | Sep. 30, 2014 | Jun. 30, 2014 | Mar. 31, 2014 | Dec. 31, 2013 | Sep. 30, 2013 | Jun. 30, 2013 | Mar. 31, 2013 | Dec. 31, 2014 reportable_segment | Dec. 31, 2013 | Dec. 31, 2012
Segment Information [Line Items] |  |  |  |  |  |  |  |  |  |  |
Number of reportable segments |  |  |  |  |  |  |  |  | 2 us-gaap_NumberOfReportableSegments |  |
Gross premiums written |  |  |  |  |  |  |  |  | $ 4,711,519 us-gaap_PremiumsWrittenGross | $ 4,697,041 us-gaap_PremiumsWrittenGross | $ 4,139,643 us-gaap_PremiumsWrittenGross
Net premiums written |  |  |  |  |  |  |  |  | 3,906,975 us-gaap_PremiumsWrittenNet | 3,928,200 us-gaap_PremiumsWrittenNet | 3,337,456 us-gaap_PremiumsWrittenNet
Net premiums earned | 958,517 us-gaap_PremiumsEarnedNet | 966,138 us-gaap_PremiumsEarnedNet | 1,000,400 us-gaap_PremiumsEarnedNet | 945,949 us-gaap_PremiumsEarnedNet | 941,911 us-gaap_PremiumsEarnedNet | 945,242 us-gaap_PremiumsEarnedNet | 945,873 us-gaap_PremiumsEarnedNet | 874,039 us-gaap_PremiumsEarnedNet | 3,870,999 us-gaap_PremiumsEarnedNet | 3,707,065 us-gaap_PremiumsEarnedNet | 3,415,463 us-gaap_PremiumsEarnedNet
Other insurance related income (loss) |  |  |  |  |  |  |  |  | 650 us-gaap_OtherOperatingIncome | 4,424 us-gaap_OtherOperatingIncome | 2,676 us-gaap_OtherOperatingIncome
Net losses and loss expenses |  |  |  |  |  |  |  |  | (2,186,722)us-gaap_PolicyholderBenefitsAndClaimsIncurredNet | (2,134,195)us-gaap_PolicyholderBenefitsAndClaimsIncurredNet | (2,096,028)us-gaap_PolicyholderBenefitsAndClaimsIncurredNet
Acquisition costs |  |  |  |  |  |  |  |  | (737,197)us-gaap_DeferredPolicyAcquisitionCostAmortizationExpense | (664,191)us-gaap_DeferredPolicyAcquisitionCostAmortizationExpense | (627,653)us-gaap_DeferredPolicyAcquisitionCostAmortizationExpense
General and administrative expenses |  |  |  |  |  |  |  |  | (621,876)us-gaap_SellingGeneralAndAdministrativeExpense | (575,390)us-gaap_SellingGeneralAndAdministrativeExpense | (560,981)us-gaap_SellingGeneralAndAdministrativeExpense
Underwriting income | 112,720 axs_UnderwritingIncomeLossNet | 113,464 axs_UnderwritingIncomeLossNet | 126,581 axs_UnderwritingIncomeLossNet | 108,766 axs_UnderwritingIncomeLossNet | 94,159 axs_UnderwritingIncomeLossNet | 153,088 axs_UnderwritingIncomeLossNet | 9,921 axs_UnderwritingIncomeLossNet | 170,799 axs_UnderwritingIncomeLossNet |  |  |
Net investment income | 78,595 axs_InvestmentIncomeNetForInvestmentsAndCashAndCashEquivalents | 66,562 axs_InvestmentIncomeNetForInvestmentsAndCashAndCashEquivalents | 114,867 axs_InvestmentIncomeNetForInvestmentsAndCashAndCashEquivalents | 82,744 axs_InvestmentIncomeNetForInvestmentsAndCashAndCashEquivalents | 113,863 axs_InvestmentIncomeNetForInvestmentsAndCashAndCashEquivalents | 103,429 axs_InvestmentIncomeNetForInvestmentsAndCashAndCashEquivalents | 83,112 axs_InvestmentIncomeNetForInvestmentsAndCashAndCashEquivalents | 108,908 axs_InvestmentIncomeNetForInvestmentsAndCashAndCashEquivalents | 342,766 axs_InvestmentIncomeNetForInvestmentsAndCashAndCashEquivalents | 409,312 axs_InvestmentIncomeNetForInvestmentsAndCashAndCashEquivalents | 380,957 axs_InvestmentIncomeNetForInvestmentsAndCashAndCashEquivalents
Net realized investment gains | 10,779 axs_AvailableForSaleSecuritiesGrossRealizedGainLossNetIncludingDerivativesGainsLosses | 77,448 axs_AvailableForSaleSecuritiesGrossRealizedGainLossNetIncludingDerivativesGainsLosses | 33,261 axs_AvailableForSaleSecuritiesGrossRealizedGainLossNetIncludingDerivativesGainsLosses | 10,620 axs_AvailableForSaleSecuritiesGrossRealizedGainLossNetIncludingDerivativesGainsLosses | 19,558 axs_AvailableForSaleSecuritiesGrossRealizedGainLossNetIncludingDerivativesGainsLosses | (4,708)axs_AvailableForSaleSecuritiesGrossRealizedGainLossNetIncludingDerivativesGainsLosses | 16,235 axs_AvailableForSaleSecuritiesGrossRealizedGainLossNetIncludingDerivativesGainsLosses | 44,478 axs_AvailableForSaleSecuritiesGrossRealizedGainLossNetIncludingDerivativesGainsLosses | 132,108 axs_AvailableForSaleSecuritiesGrossRealizedGainLossNetIncludingDerivativesGainsLosses | 75,564 axs_AvailableForSaleSecuritiesGrossRealizedGainLossNetIncludingDerivativesGainsLosses | 127,469 axs_AvailableForSaleSecuritiesGrossRealizedGainLossNetIncludingDerivativesGainsLosses
Foreign exchange (losses) gains |  |  |  |  |  |  |  |  | 104,439 us-gaap_ForeignCurrencyTransactionGainLossBeforeTax | (26,143)us-gaap_ForeignCurrencyTransactionGainLossBeforeTax | (29,512)us-gaap_ForeignCurrencyTransactionGainLossBeforeTax
Interest expense and financing costs |  |  |  |  |  |  |  |  | (74,695)us-gaap_InterestExpense | (61,979)us-gaap_InterestExpense | (61,863)us-gaap_InterestExpense
Income before income taxes |  |  |  |  |  |  |  |  | 830,472 us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments | 734,467 us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments | 550,528 us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments
Net loss and loss expense ratio |  |  |  |  |  |  |  |  | 56.50%us-gaap_LossRatio | 57.60%us-gaap_LossRatio | 61.40%us-gaap_LossRatio
Acquisition cost ratio |  |  |  |  |  |  |  |  | 19.00%us-gaap_AcquisitionCostRatio | 17.90%us-gaap_AcquisitionCostRatio | 18.40%us-gaap_AcquisitionCostRatio
General and administrative expense ratio |  |  |  |  |  |  |  |  | 16.10%us-gaap_GeneralAndAdministrativeExpenseRatio | 15.50%us-gaap_GeneralAndAdministrativeExpenseRatio | 16.40%us-gaap_GeneralAndAdministrativeExpenseRatio
Combined ratio |  |  |  |  |  |  |  |  | 91.60%us-gaap_CombinedRatio | 91.00%us-gaap_CombinedRatio | 96.20%us-gaap_CombinedRatio
Goodwill and intangible assets | 88,960 us-gaap_IntangibleAssetsNetIncludingGoodwill |  |  |  | 89,528 us-gaap_IntangibleAssetsNetIncludingGoodwill |  |  |  | 88,960 us-gaap_IntangibleAssetsNetIncludingGoodwill | 89,528 us-gaap_IntangibleAssetsNetIncludingGoodwill | 97,493 us-gaap_IntangibleAssetsNetIncludingGoodwill
Insurance [Member] |  |  |  |  |  |  |  |  |  |  |
Segment Information [Line Items] |  |  |  |  |  |  |  |  |  |  |
Net premiums earned |  |  |  |  |  |  |  |  | 1,830,544 us-gaap_PremiumsEarnedNet / us-gaap_StatementBusinessSegmentsAxis = axs_InsuranceMember | 1,722,762 us-gaap_PremiumsEarnedNet / us-gaap_StatementBusinessSegmentsAxis = axs_InsuranceMember | 1,558,058 us-gaap_PremiumsEarnedNet / us-gaap_StatementBusinessSegmentsAxis = axs_InsuranceMember
Reinsurance [Member] |  |  |  |  |  |  |  |  |  |  |
Segment Information [Line Items] |  |  |  |  |  |  |  |  |  |  |
Net premiums earned |  |  |  |  |  |  |  |  | 2,040,455 us-gaap_PremiumsEarnedNet / us-gaap_StatementBusinessSegmentsAxis = axs_ReinsuranceMember | 1,984,303 us-gaap_PremiumsEarnedNet / us-gaap_StatementBusinessSegmentsAxis = axs_ReinsuranceMember | 1,857,405 us-gaap_PremiumsEarnedNet / us-gaap_StatementBusinessSegmentsAxis = axs_ReinsuranceMember
Operating Segments [Member] |  |  |  |  |  |  |  |  |  |  |
Segment Information [Line Items] |  |  |  |  |  |  |  |  |  |  |
Gross premiums written |  |  |  |  |  |  |  |  | 4,711,519 us-gaap_PremiumsWrittenGross / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember | 4,697,041 us-gaap_PremiumsWrittenGross / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember | 4,139,643 us-gaap_PremiumsWrittenGross / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember
Net premiums written |  |  |  |  |  |  |  |  | 3,906,975 us-gaap_PremiumsWrittenNet / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember | 3,928,200 us-gaap_PremiumsWrittenNet / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember | 3,337,456 us-gaap_PremiumsWrittenNet / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember
Net premiums earned |  |  |  |  |  |  |  |  | 3,870,999 us-gaap_PremiumsEarnedNet / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember | 3,707,065 us-gaap_PremiumsEarnedNet / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember | 3,415,463 us-gaap_PremiumsEarnedNet / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember
Other insurance related income (loss) |  |  |  |  |  |  |  |  | 650 us-gaap_OtherOperatingIncome / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember | 4,424 us-gaap_OtherOperatingIncome / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember | 2,676 us-gaap_OtherOperatingIncome / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember
Net losses and loss expenses |  |  |  |  |  |  |  |  | (2,186,722)us-gaap_PolicyholderBenefitsAndClaimsIncurredNet / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember | (2,134,195)us-gaap_PolicyholderBenefitsAndClaimsIncurredNet / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember | (2,096,028)us-gaap_PolicyholderBenefitsAndClaimsIncurredNet / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember
Acquisition costs |  |  |  |  |  |  |  |  | (737,197)us-gaap_DeferredPolicyAcquisitionCostAmortizationExpense / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember | (664,191)us-gaap_DeferredPolicyAcquisitionCostAmortizationExpense / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember | (627,653)us-gaap_DeferredPolicyAcquisitionCostAmortizationExpense / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember
General and administrative expenses |  |  |  |  |  |  |  |  | (486,201)us-gaap_SellingGeneralAndAdministrativeExpense / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember | (485,134)us-gaap_SellingGeneralAndAdministrativeExpense / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember | (431,321)us-gaap_SellingGeneralAndAdministrativeExpense / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember
Underwriting income |  |  |  |  |  |  |  |  | 461,529 axs_UnderwritingIncomeLossNet / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember | 427,969 axs_UnderwritingIncomeLossNet / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember | 263,137 axs_UnderwritingIncomeLossNet / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember
Operating Segments [Member] | Insurance [Member] |  |  |  |  |  |  |  |  |  |  |
Segment Information [Line Items] |  |  |  |  |  |  |  |  |  |  |
Gross premiums written |  |  |  |  |  |  |  |  | 2,535,415 us-gaap_PremiumsWrittenGross / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_InsuranceMember | 2,559,138 us-gaap_PremiumsWrittenGross / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_InsuranceMember | 2,309,481 us-gaap_PremiumsWrittenGross / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_InsuranceMember
Net premiums written |  |  |  |  |  |  |  |  | 1,779,501 us-gaap_PremiumsWrittenNet / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_InsuranceMember | 1,813,538 us-gaap_PremiumsWrittenNet / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_InsuranceMember | 1,522,245 us-gaap_PremiumsWrittenNet / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_InsuranceMember
Net premiums earned |  |  |  |  |  |  |  |  | 1,830,544 us-gaap_PremiumsEarnedNet / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_InsuranceMember | 1,722,762 us-gaap_PremiumsEarnedNet / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_InsuranceMember | 1,558,058 us-gaap_PremiumsEarnedNet / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_InsuranceMember
Other insurance related income (loss) |  |  |  |  |  |  |  |  | (11)us-gaap_OtherOperatingIncome / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_InsuranceMember | 2,436 us-gaap_OtherOperatingIncome / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_InsuranceMember | 2,676 us-gaap_OtherOperatingIncome / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_InsuranceMember
Net losses and loss expenses |  |  |  |  |  |  |  |  | (1,131,880)us-gaap_PolicyholderBenefitsAndClaimsIncurredNet / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_InsuranceMember | (1,050,402)us-gaap_PolicyholderBenefitsAndClaimsIncurredNet / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_InsuranceMember | (953,564)us-gaap_PolicyholderBenefitsAndClaimsIncurredNet / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_InsuranceMember
Acquisition costs |  |  |  |  |  |  |  |  | (278,804)us-gaap_DeferredPolicyAcquisitionCostAmortizationExpense / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_InsuranceMember | (242,363)us-gaap_DeferredPolicyAcquisitionCostAmortizationExpense / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_InsuranceMember | (226,859)us-gaap_DeferredPolicyAcquisitionCostAmortizationExpense / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_InsuranceMember
General and administrative expenses |  |  |  |  |  |  |  |  | (341,214)us-gaap_SellingGeneralAndAdministrativeExpense / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_InsuranceMember | (347,684)us-gaap_SellingGeneralAndAdministrativeExpense / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_InsuranceMember | (314,834)us-gaap_SellingGeneralAndAdministrativeExpense / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_InsuranceMember
Underwriting income |  |  |  |  |  |  |  |  | 78,635 axs_UnderwritingIncomeLossNet / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_InsuranceMember | 84,749 axs_UnderwritingIncomeLossNet / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_InsuranceMember | 65,477 axs_UnderwritingIncomeLossNet / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_InsuranceMember
Net loss and loss expense ratio |  |  |  |  |  |  |  |  | 61.80%us-gaap_LossRatio / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_InsuranceMember | 61.00%us-gaap_LossRatio / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_InsuranceMember | 61.20%us-gaap_LossRatio / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_InsuranceMember
Acquisition cost ratio |  |  |  |  |  |  |  |  | 15.20%us-gaap_AcquisitionCostRatio / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_InsuranceMember | 14.10%us-gaap_AcquisitionCostRatio / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_InsuranceMember | 14.60%us-gaap_AcquisitionCostRatio / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_InsuranceMember
General and administrative expense ratio |  |  |  |  |  |  |  |  | 18.70%us-gaap_GeneralAndAdministrativeExpenseRatio / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_InsuranceMember | 20.10%us-gaap_GeneralAndAdministrativeExpenseRatio / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_InsuranceMember | 20.20%us-gaap_GeneralAndAdministrativeExpenseRatio / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_InsuranceMember
Combined ratio |  |  |  |  |  |  |  |  | 95.70%us-gaap_CombinedRatio / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_InsuranceMember | 95.20%us-gaap_CombinedRatio / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_InsuranceMember | 96.00%us-gaap_CombinedRatio / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_InsuranceMember
Goodwill and intangible assets | 88,960 us-gaap_IntangibleAssetsNetIncludingGoodwill / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_InsuranceMember |  |  |  | 89,528 us-gaap_IntangibleAssetsNetIncludingGoodwill / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_InsuranceMember |  |  |  | 88,960 us-gaap_IntangibleAssetsNetIncludingGoodwill / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_InsuranceMember | 89,528 us-gaap_IntangibleAssetsNetIncludingGoodwill / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_InsuranceMember | 97,493 us-gaap_IntangibleAssetsNetIncludingGoodwill / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_InsuranceMember
Operating Segments [Member] | Reinsurance [Member] |  |  |  |  |  |  |  |  |  |  |
Segment Information [Line Items] |  |  |  |  |  |  |  |  |  |  |
Gross premiums written |  |  |  |  |  |  |  |  | 2,176,104 us-gaap_PremiumsWrittenGross / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_ReinsuranceMember | 2,137,903 us-gaap_PremiumsWrittenGross / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_ReinsuranceMember | 1,830,162 us-gaap_PremiumsWrittenGross / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_ReinsuranceMember
Net premiums written |  |  |  |  |  |  |  |  | 2,127,474 us-gaap_PremiumsWrittenNet / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_ReinsuranceMember | 2,114,662 us-gaap_PremiumsWrittenNet / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_ReinsuranceMember | 1,815,211 us-gaap_PremiumsWrittenNet / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_ReinsuranceMember
Net premiums earned |  |  |  |  |  |  |  |  | 2,040,455 us-gaap_PremiumsEarnedNet / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_ReinsuranceMember | 1,984,303 us-gaap_PremiumsEarnedNet / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_ReinsuranceMember | 1,857,405 us-gaap_PremiumsEarnedNet / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_ReinsuranceMember
Other insurance related income (loss) |  |  |  |  |  |  |  |  | 661 us-gaap_OtherOperatingIncome / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_ReinsuranceMember | 1,988 us-gaap_OtherOperatingIncome / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_ReinsuranceMember | 0 us-gaap_OtherOperatingIncome / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_ReinsuranceMember
Net losses and loss expenses |  |  |  |  |  |  |  |  | (1,054,842)us-gaap_PolicyholderBenefitsAndClaimsIncurredNet / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_ReinsuranceMember | (1,083,793)us-gaap_PolicyholderBenefitsAndClaimsIncurredNet / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_ReinsuranceMember | (1,142,464)us-gaap_PolicyholderBenefitsAndClaimsIncurredNet / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_ReinsuranceMember
Acquisition costs |  |  |  |  |  |  |  |  | (458,393)us-gaap_DeferredPolicyAcquisitionCostAmortizationExpense / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_ReinsuranceMember | (421,828)us-gaap_DeferredPolicyAcquisitionCostAmortizationExpense / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_ReinsuranceMember | (400,794)us-gaap_DeferredPolicyAcquisitionCostAmortizationExpense / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_ReinsuranceMember
General and administrative expenses |  |  |  |  |  |  |  |  | (144,987)us-gaap_SellingGeneralAndAdministrativeExpense / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_ReinsuranceMember | (137,450)us-gaap_SellingGeneralAndAdministrativeExpense / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_ReinsuranceMember | (116,487)us-gaap_SellingGeneralAndAdministrativeExpense / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_ReinsuranceMember
Underwriting income |  |  |  |  |  |  |  |  | 382,894 axs_UnderwritingIncomeLossNet / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_ReinsuranceMember | 343,220 axs_UnderwritingIncomeLossNet / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_ReinsuranceMember | 197,660 axs_UnderwritingIncomeLossNet / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_ReinsuranceMember
Net loss and loss expense ratio |  |  |  |  |  |  |  |  | 51.70%us-gaap_LossRatio / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_ReinsuranceMember | 54.60%us-gaap_LossRatio / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_ReinsuranceMember | 61.50%us-gaap_LossRatio / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_ReinsuranceMember
Acquisition cost ratio |  |  |  |  |  |  |  |  | 22.50%us-gaap_AcquisitionCostRatio / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_ReinsuranceMember | 21.30%us-gaap_AcquisitionCostRatio / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_ReinsuranceMember | 21.60%us-gaap_AcquisitionCostRatio / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_ReinsuranceMember
General and administrative expense ratio |  |  |  |  |  |  |  |  | 7.10%us-gaap_GeneralAndAdministrativeExpenseRatio / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_ReinsuranceMember | 6.90%us-gaap_GeneralAndAdministrativeExpenseRatio / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_ReinsuranceMember | 6.30%us-gaap_GeneralAndAdministrativeExpenseRatio / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_ReinsuranceMember
Combined ratio |  |  |  |  |  |  |  |  | 81.30%us-gaap_CombinedRatio / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_ReinsuranceMember | 82.80%us-gaap_CombinedRatio / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_ReinsuranceMember | 89.40%us-gaap_CombinedRatio / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_ReinsuranceMember
Goodwill and intangible assets | 0 us-gaap_IntangibleAssetsNetIncludingGoodwill / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_ReinsuranceMember |  |  |  | 0 us-gaap_IntangibleAssetsNetIncludingGoodwill / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_ReinsuranceMember |  |  |  | 0 us-gaap_IntangibleAssetsNetIncludingGoodwill / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_ReinsuranceMember | 0 us-gaap_IntangibleAssetsNetIncludingGoodwill / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_ReinsuranceMember | 0 us-gaap_IntangibleAssetsNetIncludingGoodwill / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = axs_ReinsuranceMember
Corporate, Non-Segment [Member] |  |  |  |  |  |  |  |  |  |  |
Segment Information [Line Items] |  |  |  |  |  |  |  |  |  |  |
General and administrative expenses |  |  |  |  |  |  |  |  | (135,675)us-gaap_SellingGeneralAndAdministrativeExpense / us-gaap_ConsolidationItemsAxis = us-gaap_CorporateNonSegmentMember | (90,256)us-gaap_SellingGeneralAndAdministrativeExpense / us-gaap_ConsolidationItemsAxis = us-gaap_CorporateNonSegmentMember | (129,660)us-gaap_SellingGeneralAndAdministrativeExpense / us-gaap_ConsolidationItemsAxis = us-gaap_CorporateNonSegmentMember
Significant Reconciling Items [Member] |  |  |  |  |  |  |  |  |  |  |
Segment Information [Line Items] |  |  |  |  |  |  |  |  |  |  |
Net investment income |  |  |  |  |  |  |  |  | 342,766 axs_InvestmentIncomeNetForInvestmentsAndCashAndCashEquivalents / us-gaap_ConsolidationItemsAxis = us-gaap_MaterialReconcilingItemsMember | 409,312 axs_InvestmentIncomeNetForInvestmentsAndCashAndCashEquivalents / us-gaap_ConsolidationItemsAxis = us-gaap_MaterialReconcilingItemsMember | 380,957 axs_InvestmentIncomeNetForInvestmentsAndCashAndCashEquivalents / us-gaap_ConsolidationItemsAxis = us-gaap_MaterialReconcilingItemsMember
Net realized investment gains |  |  |  |  |  |  |  |  | 132,108 axs_AvailableForSaleSecuritiesGrossRealizedGainLossNetIncludingDerivativesGainsLosses / us-gaap_ConsolidationItemsAxis = us-gaap_MaterialReconcilingItemsMember | 75,564 axs_AvailableForSaleSecuritiesGrossRealizedGainLossNetIncludingDerivativesGainsLosses / us-gaap_ConsolidationItemsAxis = us-gaap_MaterialReconcilingItemsMember | 127,469 axs_AvailableForSaleSecuritiesGrossRealizedGainLossNetIncludingDerivativesGainsLosses / us-gaap_ConsolidationItemsAxis = us-gaap_MaterialReconcilingItemsMember
Foreign exchange (losses) gains |  |  |  |  |  |  |  |  | 104,439 us-gaap_ForeignCurrencyTransactionGainLossBeforeTax / us-gaap_ConsolidationItemsAxis = us-gaap_MaterialReconcilingItemsMember | (26,143)us-gaap_ForeignCurrencyTransactionGainLossBeforeTax / us-gaap_ConsolidationItemsAxis = us-gaap_MaterialReconcilingItemsMember | (29,512)us-gaap_ForeignCurrencyTransactionGainLossBeforeTax / us-gaap_ConsolidationItemsAxis = us-gaap_MaterialReconcilingItemsMember
Interest expense and financing costs |  |  |  |  |  |  |  |  | $ (74,695)us-gaap_InterestExpense / us-gaap_ConsolidationItemsAxis = us-gaap_MaterialReconcilingItemsMember | $ (61,979)us-gaap_InterestExpense / us-gaap_ConsolidationItemsAxis = us-gaap_MaterialReconcilingItemsMember | $ (61,863)us-gaap_InterestExpense / us-gaap_ConsolidationItemsAxis = us-gaap_MaterialReconcilingItemsMember

X
- Definition This item represents the difference between the gross realized gains and losses realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities. Additionally, this item would include any losses recognized for other than temporary impairments (OTTI) of the subject investments in debt and equity securities, the change in fair value of investment-related derivatives not designated as hedges and any hedge ineffectiveness recognized in earnings in relation to investment portfolio-related fair value hedges. + References No definition available. + Details
Name: | axs_AvailableForSaleSecuritiesGrossRealizedGainLossNetIncludingDerivativesGainsLosses
Namespace Prefix: | axs_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The net gain or loss (both realized and unrealized) related to investments in certain entities that calculate net asset value per share and the amount after accretion (amortization) of discount (premium) of interest income and dividend income on nonoperating securities, net of investment expense. + References No definition available. + Details
Name: | axs_InvestmentIncomeNetForInvestmentsAndCashAndCashEquivalents
Namespace Prefix: | axs_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Net premiums earned less: net losses and loss expenses, acquisition costs and general and administrative expenses directly related to underwriting activities. + References No definition available. + Details
Name: | axs_UnderwritingIncomeLossNet
Namespace Prefix: | axs_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Ratio of non-life acquisition costs to non-life net premiums earned. + References No definition available. + Details
Name: | us-gaap_AcquisitionCostRatio
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Ratio of non-life losses and loss expenses, non-life acquisition expenses and non-life general and administrative expenses, to non-life net premiums earned. + References No definition available. + Details
Name: | us-gaap_CombinedRatio
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of expense related to deferred policy acquisition costs. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 16 -Article 12 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 225 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-04.7(a)) -URI http://asc.fasb.org/extlink&oid=6879464&loc=d3e573970-122913 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Paragraph 7 -Article 7 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 18 -Article 12 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 30 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=35755530&loc=d3e11264-158415 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 30 -Section 35 -Paragraph 11 -URI http://asc.fasb.org/extlink&oid=28247317&loc=d3e10157-158409 Reference 7: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 20 -Section 45 -Paragraph 2 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=6480726&loc=d3e6691-158385 + Details
Name: | us-gaap_DeferredPolicyAcquisitionCostAmortizationExpense
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount before tax of foreign currency transaction realized and unrealized gain (loss) recognized in the income statement. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 830 -SubTopic 20 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6450189&loc=d3e30690-110894 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 830 -SubTopic 20 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6450222&loc=d3e30840-110895 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 830 -SubTopic 20 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6450189&loc=d3e30700-110894 + Details
Name: | us-gaap_ForeignCurrencyTransactionGainLossBeforeTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Ratio of non-life general and administrative expenses to non-life net premiums earned. + References No definition available. + Details
Name: | us-gaap_GeneralAndAdministrativeExpenseRatio
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Sum of operating profit and nonoperating income or expense before Income or Loss from equity method investments, income taxes, extraordinary items, and noncontrolling interest. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08.(h)(1)(i)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690 + Details
Name: | us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Carrying amount of finite-lived intangible assets, indefinite-lived intangible assets and goodwill. Goodwill is an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. Intangible assets are assets, not including financial assets, lacking physical substance. + References No definition available. + Details
Name: | us-gaap_IntangibleAssetsNetIncludingGoodwill
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of the cost of borrowed funds accounted for as interest expense. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 20 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6450988&loc=d3e26243-108391 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 225 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04.9) -URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Paragraph 9 -Article 9 + Details
Name: | us-gaap_InterestExpense
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Ratio of non-life losses and loss expenses to non-life net premiums earned. + References No definition available. + Details
Name: | us-gaap_LossRatio
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements. + References No definition available. + Details
Name: | us-gaap_NumberOfReportableSegments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition The total amount of other operating income, the components of which are not separately disclosed on the income statement, from items that are associated with the entity's normal revenue producing operation. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 225 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.1) -URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688 + Details
Name: | us-gaap_OtherOperatingIncome
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount, after effects of policies assumed or ceded, of expense related to the provision for policy benefits and costs incurred. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 225 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-04.5) -URI http://asc.fasb.org/extlink&oid=6879464&loc=d3e573970-122913 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Paragraph 5 -Article 7 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 20 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=6480758&loc=d3e6811-158387 + Details
Name: | us-gaap_PolicyholderBenefitsAndClaimsIncurredNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount, after premiums ceded to other entities and premiums assumed by the entity, of premiums earned. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 17 -Article 12 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 235 -Section S99 -Paragraph 2 -Subparagraph (SX 210.12-17) -URI http://asc.fasb.org/extlink&oid=34713774&loc=d3e574992-122915 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 225 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-04.1) -URI http://asc.fasb.org/extlink&oid=6879464&loc=d3e573970-122913 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Paragraph 1 -Article 7 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 605 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6486672&loc=d3e27261-158547 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 225 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04.13(c)) -URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882 + Details
Name: | us-gaap_PremiumsEarnedNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of direct and assumed premiums written. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 605 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6486672&loc=d3e27261-158547 + Details
Name: | us-gaap_PremiumsWrittenGross
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount, after premiums ceded to other entities and premiums assumed by the entity, of premiums written. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 17 -Article 12 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 605 -Section 50 -Paragraph 1 -Subparagraph (b),(c) -URI http://asc.fasb.org/extlink&oid=6486672&loc=d3e27261-158547 + Details
Name: | us-gaap_PremiumsWrittenNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | us-gaap_SegmentReportingInformationLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The aggregate total costs related to selling a firm's product and services, as well as all other general and administrative expenses. Direct selling expenses (for example, credit, warranty, and advertising) are expenses that can be directly linked to the sale of specific products. Indirect selling expenses are expenses that cannot be directly linked to the sale of specific products, for example telephone expenses, Internet, and postal charges. General and administrative expenses include salaries of non-sales personnel, rent, utilities, communication, etc. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 225 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.4) -URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 4 -Article 5 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 330 -SubTopic 10 -Section 30 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=34747878&loc=d3e3636-108311 + Details
Name: | us-gaap_SellingGeneralAndAdministrativeExpense
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | us-gaap_ConsolidationItemsAxis=us-gaap_CorporateNonSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ConsolidationItemsAxis=us-gaap_MaterialReconcilingItemsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ConsolidationItemsAxis=us-gaap_OperatingSegmentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=axs_InsuranceMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=axs_ReinsuranceMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |