v2.4.0.6

DERIVATIVE INSTRUMENTS (TABLES) | 12 Months Ended
--- | ---
Dec. 31, 2011
DERIVATIVE INSTRUMENTS [Abstract] |
LOCATION AND AMOUNTS OF DERIVATIVE FAIR VALUES ON THE CONSOLIDATED BALANCE SHEET [Table Text Block] |
|  |  | December 31, 2011 |  | December 31, 2010 |
|  |  |  | Derivative Notional Amount |  |  | Asset Derivative Fair Value(1) |  |  | Liability Derivative Fair Value(1) |  |  | Derivative Notional Amount |  |  | Asset Derivative Fair Value(1) |  |  | Liability Derivative Fair Value(1) |
| Derivatives designated as hedging instruments |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
| Foreign exchange forward contracts | $ | 540,176 |  | $ | 16,519 |  | $ | - |  | $ | 612,845 |  | $ | - |  | $ | 13,748 |
| Derivatives not designated as hedging instruments |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
| Relating to investment portfolio: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
| Foreign exchange forward contracts |  | 287,711 |  |  | 7,012 |  |  | 1,783 |  |  | 154,990 |  |  | 2,182 |  |  | 746 |
| Relating to underwriting portfolio: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
| Foreign exchange forward contracts | $ | 955,728 |  |  | 14,644 |  |  | 252 |  | $ | 110,564 |  |  | 4,459 |  |  | 492 |
| Total derivatives |  |  |  |  | $ | 38,175 |  | $ | 2,035 |  |  |  |  | $ | 6,641 |  | $ | 14,986 |
(1) Asset and liability derivatives are classified within other assets and other liabilities on the consolidated balance sheets.
TOTAL UNREALIZED AND REALIZED GAINS (LOSSES) ON DERIVATIVES NOT DESIGNATED AS HEDGES RECORDED IN EARNINGS [Table Text Block] |
| Year ended December 31, |  |  | 2011 |  |  | 2010 |  |  | 2009 |
| Foreign exchange forward contracts |  |  | $ | 11,682 |  | $ | 35,886 |  | $ | (13,655) |
| Hedged investment portfolio |  |  |  | (16,085) |  |  | (30,063) |  |  | 16,565 |
| Hedge ineffectiveness recognized in earnings |  | $ | (4,403) |  | $ | 5,823 |  | $ | 2,910 |
NET EARNINGS IMPACT OF FAIR VALUE HEDGES [Table Text Block] |
The following table provides the total unrealized and realized gains (losses) on derivatives recorded in earnings:
|  |  |  | Amount of Gain (Loss) Recognized in Income on Derivative |
|  | Location of Gain (Loss) Recognized |  |  |  |  |  |  |  |
|  | in Income on Derivative |  | 2011 |  |  | 2010 |  |  | 2009 |
| Derivatives not designated as hedging instruments |  |  |  |  |  |  |  |  |
| Relating to investment portfolio: |  |  |  |  |  |  |  |  |
| Foreign exchange forward contracts | Net realized investment gains (losses) | $ | 4,431 |  | $ | (3,641) |  | $ | (1,032) |
| Relating to underwriting portfolio: |  |  |  |  |  |  |  |  |
| Foreign exchange forward contracts | Foreign exchange gains (losses) |  | 33,893 |  |  | 9,596 |  |  | (10,429) |
| Currency collar options | Foreign exchange gains (losses) |  | 267 |  |  | - |  |  | 2,428 |
| Longevity risk derivative | Other insurance related income (loss) |  | - |  |  | - |  |  | (132,595) |
| Catastrophe-related risk | Other insurance related income (loss) |  | - |  |  | - |  |  | 45 |
| Total |  | $ | 38,591 |  | $ | 5,955 |  | $ | (141,583) |

X
- Definition Schedule showing the composition of the net gain (loss) recognized in earnings during the reporting period representing the amount of the fair value hedges' ineffetiveness. + References No definition available. + Details
Name: | axs_ScheduleOfFairValueHedgeIneffectivenessTableTextBlock
Namespace Prefix: | axs_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

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

X
- Definition Tabular disclosure of the location and amount of gains and losses reported in the statement of financial performance, or when applicable, the statement of financial position. For example, (a) gains and losses recognized in the income statement on derivative instruments designated and qualifying as hedging instruments in fair value hedges and related hedged items designated and qualifying in fair value hedges and (b) gains and losses initially recognized in other comprehensive income on derivative instruments designated and qualifying as cash flow hedges. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 133 -Paragraph 205G -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4C -URI http://asc.fasb.org/extlink&oid=6935481&loc=SL5624171-113959 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4A -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6935481&loc=SL5618551-113959 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 133 -Paragraph 44C -Subparagraph b -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. + Details
Name: | us-gaap_ScheduleOfDerivativeInstrumentsGainLossInStatementOfFinancialPerformanceTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the location and fair value amounts of derivative instruments (and nonderivative instruments that are designated and qualify as hedging instruments) reported in the statement of financial position. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4B -URI http://asc.fasb.org/extlink&oid=6935481&loc=SL5624163-113959 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 133 -Paragraph 205G -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 133 -Paragraph 44C -Subparagraph a -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. + Details
Name: | us-gaap_ScheduleOfDerivativeInstrumentsInStatementOfFinancialPositionFairValueTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration