XML 101 R77.htm IDEA: XBRL DOCUMENT
v3.10.0.1

INVESTMENTS - Securities narrative (Details) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2018 | Dec. 31, 2017
Schedule Of Available For Sale Securities [Line Items] |  |
Fair value | $ 11,435,347 | $ 12,622,006
Total Unrealized Losses | 215,000 | 91,000
Gross unrealized losses | (17,882) | (1,883)
Fair value | 381,633 | 635,511
Non-U.S. government |  |
Schedule Of Available For Sale Securities [Line Items] |  |
Fair value | 493,016 | 806,299
Total Unrealized Losses | 16,120 | 9,523
Non-U.S. government | Eurozone |  |
Schedule Of Available For Sale Securities [Line Items] |  |
Fair value | 29,000 | 185,000
CMBS |  |
Schedule Of Available For Sale Securities [Line Items] |  |
Fair value | 1,092,530 | 777,728
Total Unrealized Losses | $ 13,795 | $ 3,125
CMBS | Weighted Average |  |
Schedule Of Available For Sale Securities [Line Items] |  |
Subordination percentage input for determining credit losses | 31.00% | 29.00%
Non-Agency RMBS |  |
Schedule Of Available For Sale Securities [Line Items] |  |
Fair value | $ 40,687 | $ 46,831
Total Unrealized Losses | 1,282 | 799
Non-Agency RMBS | Prime |  |
Schedule Of Available For Sale Securities [Line Items] |  |
Fair value | 31,000 | 34,000
Non-Agency RMBS | Alt A |  |
Schedule Of Available For Sale Securities [Line Items] |  |
Fair value | $ 5,000 | $ 8,000

X
- Definition This item represents the current level of subordination of the entity's receipt of consideration should the assets underlying the security be liquidated when the level of subordination was considered as one of the potential factors in reaching a conclusion that the available-for-sale investments are other than temporarily impaired and the amount of such impairment determined to be related to credit loss recognized in earnings. + References No definition available. + Details
Name: | axs_OtherThanTemporaryImpairmentLossesInvestmentsAvailableForSaleSecuritiesPortionRecognizedInEarningsNetQualitativeDisclosuresLevelOfSubordinationPercentage
Namespace Prefix: | axs_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 45 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=109979856&loc=d3e26610-111562 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (aa) -URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27161-111563 + Details
Name: | us-gaap_AvailableForSaleSecuritiesDebtSecurities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of accumulated unrealized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in unrealized loss position. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 6 -Subparagraph (a)(2) -URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27290-111563 + Details
Name: | us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 45 -Paragraph 1A -URI http://asc.fasb.org/extlink&oid=99377092&loc=SL75136599-209740 + Details
Name: | us-gaap_EquitySecuritiesFvNi
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of unrealized loss on investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 321 -SubTopic 10 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=84241550&loc=SL75117546-209714 + Details
Name: | us-gaap_EquitySecuritiesFvNiUnrealizedLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_ForeignGovernmentDebtSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | invest_InvestmentGeographicRegionAxis=axs_EurozoneMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_CommercialMortgageBackedSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_WeightedAverageMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InternalCreditAssessmentAxis=us-gaap_PrimeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InternalCreditAssessmentAxis=axs_AltaMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |