AXIS Capital Holdings Limited (AXS) 10-K 21 Feb 14 2013 FY Annual report Financial data

DOCUMENT_AND_ENTITY_INFORMATIO

DOCUMENT AND ENTITY INFORMATION (USD $)	12 Months Ended
In Billions, except Share data, unless otherwise specified	Dec. 31, 2013	Feb. 10, 2014	Jun. 30, 2013
DOCUMENT AND ENTITY INFORMATION [ABSTRACT]	'	'	'
Document Type	'10-K	'	'
Amendment Flag	'false	'	'
Document Period End Date	31-Dec-13	'	'
Document Fiscal Year Focus	'2013	'	'
Document Fiscal Period Focus	'FY	'	'
Entity Registrant Name	'AXIS CAPITAL HOLDINGS LTD	'	'
Entity Central Index Key	'0001214816	'	'
Current Fiscal Year End Date	'--12-31	'	'
Entity Current Reporting Status	'Yes	'	'
Entity Filer Category	'Large Accelerated Filer	'	'
Entity Common Stock, Shares Outstanding	'	112,059,576	'
Entity Voluntary Filer	'No	'	'
Entity Well-known Seasoned Issuer	'Yes	'	'
Entity Public Float	'	'	$5.10

CONSOLIDATED_BALANCE_SHEETS

CONSOLIDATED BALANCE SHEETS (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Assets	'	'
Fixed maturities, available for sale, at fair value (Amortized cost 2013: $11,987,146; 2012: $11,605,672)	$11,986,327	$11,928,049
Equity securities, available for sale, at fair value (Cost 2013: $566,219; 2012: $608,306)	701,987	666,548
Other investments, at fair value	1,045,810	843,437
Short-term investments, at fair value and amortized cost	46,212	108,860
Total investments	13,780,336	13,546,894
Cash and cash equivalents	923,326	759,817
Restricted cash and cash equivalents	64,550	90,733
Accrued interest receivable	97,132	97,220
Insurance and reinsurance premium balances receivable	1,688,957	1,474,821
Reinsurance recoverable on unpaid and paid losses	1,929,988	1,863,819
Deferred acquisition costs	456,122	389,248
Prepaid reinsurance premiums	330,261	315,676
Receivable for investments sold	1,199	1,254
Goodwill and intangible assets	89,528	97,493
Other assets	273,385	215,369
Total assets	19,634,784	18,852,344
Liabilities	'	'
Reserve for losses and loss expenses	9,582,140	9,058,731
Unearned premiums	2,683,849	2,454,692
Insurance and reinsurance balances payable	234,412	270,739
Senior notes	995,855	995,245
Payable for investments purchased	21,744	64,553
Other liabilities	248,822	228,623
Total liabilities	13,766,822	13,072,583
Shareholders' equity	'	'
Preferred shares	627,843	502,843
Common shares (2013: 174,134; 2012: 171,867 shares issued and 2013: 109,485; 2012: 117,920 shares outstanding)	2,174	2,146
Additional paid-in capital	2,240,125	2,179,034
Accumulated other comprehensive income	117,825	362,622
Retained earnings	5,062,706	4,497,789
Treasury shares, at cost (2013: 64,649; 2012: 53,947 shares)	-2,232,711	-1,764,673
Total shareholders' equity attributable to AXIS Capital	5,817,962	5,779,761
Noncontrolling interests	50,000	0
Total shareholders' equity	5,867,962	5,779,761
Total liabilities and shareholders' equity	$19,634,784	$18,852,344

CONSOLIDATED_BALANCE_SHEETS_Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Statement of Financial Position [Abstract]	'	'
Fixed maturities, available for sale, amortized cost	$11,987,146	$11,605,672
Equity securities, available for sale, cost	566,219	608,306
Short term investments, amortized cost	$46,212	$108,860
Common shares, shares issued	174,134	171,867
Common shares, shares outstanding	109,485	117,920
Treasury shares, shares	64,649	53,947

CONSOLIDATED_STATEMENTS_OF_OPE

CONSOLIDATED STATEMENTS OF OPERATIONS (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Revenues	'	'	'
Net premiums earned	$3,707,065	$3,415,463	$3,314,961
Net investment income	409,312	380,957	362,430
Other insurance related income	4,424	2,676	2,396
Net realized investment gains:	'	'	'
Other-than-temporary impairment (OTTI) losses	-9,362	-24,234	-16,446
Non-credit portion of OTTI losses recognized in other comprehensive income	0	0	585
Other net realized investment gains	84,926	151,703	137,300
Total net realized investment gains	75,564	127,469	121,439
Total revenues	4,196,365	3,926,565	3,801,226
Expenses	'	'	'
Net losses and loss expenses	2,134,195	2,096,028	2,675,052
Acquisition costs	664,191	627,653	587,469
General and administrative expenses	575,390	560,981	459,151
Foreign exchange losses (gains)	26,143	29,512	-44,582
Interest expense and financing costs	61,979	61,863	62,598
Total expenses	3,461,898	3,376,037	3,739,688
Income before income taxes	734,467	550,528	61,538
Income tax expense	7,002	3,287	15,233
Net income	727,465	547,241	46,305
Preferred share dividends	40,474	38,228	36,875
Loss on repurchase of preferred shares	3,081	14,009	0
Net income available to common shareholders	$683,910	$495,004	$9,430
Net income per common share:	'	'	'
Basic net income	$6.02	$4.05	$0.08
Diluted net income	$5.93	$4	$0.07
Weighted average number of common shares outstanding - basic	113,636	122,148	122,499
Weighted average number of common shares outstanding - diluted	115,328	123,654	128,122

CONSOLIDATED_STATEMENTS_OF_COM

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Statement of Comprehensive Income [Abstract]	'	'	'
Net income	$727,465	$547,241	$46,305
Other comprehensive income (loss), net of tax:	'	'	'
Unrealized investment gains (losses) arising during the period	-161,832	348,510	74,297
Adjustment for reclassification of net realized investment gains and OTTI losses recognized in net income	-61,551	-116,278	-119,548
Unrealized investment gains (losses) arising during the period, net of reclassification adjustment	-223,383	232,232	-45,251
Non-credit portion of OTTI losses	0	0	-455
Foreign currency translation adjustment	-21,414	510	-3,045
Net change in benefit plan assets and obligations recognized in equity and reclassification adjustment	0	1,718	92
Total other comprehensive income (loss), net of tax	-244,797	234,460	-48,659
Comprehensive income (loss)	$482,668	$781,701	($2,354)

CONSOLIDATED_STATEMENTS_OF_CHA

CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY (USD $)

Total

Parent [Member]

Preferred shares [Member]

Common shares (par value) [Member]

Additional paid-in capital [Member]

Unrealized appreciation on available for sale investments, net of tax [Member]

Cumulative foreign currency translation adjustments, net of tax [Member]

Supplemental Executive Retirement Plans (SERPs) [Member]

Accumulated other comprehensive income [Member]

Retained earnings [Member]

Treasury shares, at cost [Member]

Noncontrolling interest [Member]

In Thousands

Total shareholders' equity at Dec. 31, 2010

'

'

$500,000

$1,934

$2,059,708

$161,802

$16,829

($1,810)

$176,821

$4,267,608

($1,381,101)

'

Shares issued

'

'

0

191

1,769

'

'

'

'

'

'

'

Treasury shares reissued

'

'

'

'

0

'

'

'

'

'

0

'

Issue costs on newly issued preferred shares

'

'

'

'

0

'

'

'

'

'

'

'

Value of shares repurchased and retired during the period

'

'

0

'

0

'

'

'

'

0

'

'

Stock options exercised

'

'

'

'

4,775

'

'

'

'

'

'

'

Share-based compensation expense

'

'

'

'

39,134

'

'

'

'

'

'

'

Unrealized gains (losses) arising during the period, net of reclassification adjustment

-45,251

'

'

'

'

-45,251

'

'

'

'

'

'

Non-credit portion of OTTI losses

-455

'

'

'

'

-455

'

'

'

'

'

'

Foreign currency translation adjustment

-3,045

'

'

'

'

'

-3,045

'

'

'

'

'

Net change in benefit plan assets and obligations recognized in equity

92

'

'

'

'

'

'

92

'

'

'

'

Net income

46,305

'

'

'

'

'

'

'

'

46,305

'

'

Preferred share dividends

'

'

'

'

'

'

'

'

'

-36,875

'

'

Common share dividends

'

'

'

'

'

'

'

'

'

-121,646

'

'

Shares repurchased for treasury

'

'

'

'

'

'

'

'

'

'

-65,885

'

Total shareholders' equity at Dec. 31, 2011

5,444,079

5,444,079

500,000

2,125

2,105,386

116,096

13,784

-1,718

128,162

4,155,392

-1,446,986

0

Shares issued

'

'

400,000

21

2,582

'

'

'

'

'

'

'

Treasury shares reissued

'

'

'

'

0

'

'

'

'

'

0

'

Issue costs on newly issued preferred shares

'

'

'

'

-6,456

'

'

'

'

'

'

'

Value of shares repurchased and retired during the period

'

'

-397,157

'

7,093

'

'

'

'

-14,009

'

'

Stock options exercised

'

'

'

'

2,517

'

'

'

'

'

'

'

Share-based compensation expense

'

'

'

'

67,912

'

'

'

'

'

'

'

Unrealized gains (losses) arising during the period, net of reclassification adjustment

232,232

'

'

'

'

232,232

'

'

'

'

'

'

Non-credit portion of OTTI losses

0

'

'

'

'

0

'

'

'

'

'

'

Foreign currency translation adjustment

510

'

'

'

'

'

510

'

'

'

'

'

Net change in benefit plan assets and obligations recognized in equity

1,718

'

'

'

'

'

'

1,718

'

'

'

'

Net income

547,241

'

'

'

'

'

'

'

'

547,241

'

'

Preferred share dividends

'

'

'

'

'

'

'

'

'

-38,228

'

'

Common share dividends

'

'

'

'

'

'

'

'

'

-152,607

'

'

Shares repurchased for treasury

'

'

'

'

'

'

'

'

'

'

-317,687

'

Total shareholders' equity at Dec. 31, 2012

5,779,761

5,779,761

502,843

2,146

2,179,034

348,328

14,294

0

362,622

4,497,789

-1,764,673

0

Shares issued

'

'

225,000

28

3,422

'

'

'

'

'

'

'

Treasury shares reissued

'

'

'

'

-4,225

'

'

'

'

'

4,225

'

Issue costs on newly issued preferred shares

'

'

'

'

-6,551

'

'

'

'

'

'

'

Value of shares repurchased and retired during the period

'

'

-100,000

'

3,081

'

'

'

'

-3,081

'

'

Stock options exercised

'

'

'

'

16,889

'

'

'

'

'

'

'

Share-based compensation expense

'

'

'

'

48,475

'

'

'

'

'

'

'

Unrealized gains (losses) arising during the period, net of reclassification adjustment

-223,383

'

'

'

'

-223,383

'

'

'

'

'

'

Non-credit portion of OTTI losses

0

'

'

'

'

0

'

'

'

'

'

'

Foreign currency translation adjustment

-21,414

'

'

'

'

'

-21,414

'

'

'

'

'

Net change in benefit plan assets and obligations recognized in equity

0

'

'

'

'

'

'

0

'

'

'

'

Net income

727,465

'

'

'

'

'

'

'

'

727,465

'

'

Preferred share dividends

'

'

'

'

'

'

'

'

'

-40,474

'

'

Common share dividends

'

'

'

'

'

'

'

'

'

-118,993

'

'

Shares repurchased for treasury

'

'

'

'

'

'

'

'

'

'

-472,263

'

Total shareholders' equity at Dec. 31, 2013

$5,867,962

$5,817,962

$627,843

$2,174

$2,240,125

$124,945

($7,120)

$0

$117,825

$5,062,706

($2,232,711)

$50,000

CONSOLIDATED_STATEMENTS_OF_CAS

CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Cash flows from operating activities:	'	'	'
Net income	$727,465	$547,241	$46,305
Adjustments to reconcile net income to net cash provided by operating activities:	'	'	'
Net realized investment gains	-75,564	-127,469	-121,439
Net realized and unrealized gains of other investments	-128,814	-87,623	-31,013
Amortization of fixed maturities	139,667	135,297	93,356
Other amortization and depreciation	23,272	13,821	16,905
Share-based compensation expense	57,168	67,912	39,134
Changes in:	'	'	'
Accrued interest receivable	88	1,126	-1,982
Reinsurance recoverable balances	-66,169	-93,490	-192,782
Deferred acquisition costs	-66,874	18,279	-48,227
Prepaid reinsurance premiums	-14,585	-77,053	-17,227
Reserve for loss and loss expenses	523,409	633,686	1,392,670
Unearned premiums	229,157	230	120,786
Insurance and reinsurance balances, net	-250,463	3,218	-28,562
Other items	-789	85,442	-77,782
Net cash provided by operating activities	1,096,968	1,120,617	1,190,142
Cash flows from investing activities:	'	'	'
Fixed maturities	-12,230,274	-13,513,143	-15,472,001
Equity securities	-240,926	-377,749	-603,746
Other investments	-166,835	-110,084	-220,000
Short-term investments	-198,168	-383,981	-841,124
Proceeds from the sale of:	'	'	'
Fixed maturities	10,261,256	11,144,351	13,754,436
Equity securities	323,423	468,473	222,506
Other investments	93,277	53,590	70,988
Short-term investments	197,690	354,924	710,178
Proceeds from redemption of fixed maturities	1,407,676	1,456,553	1,422,171
Proceeds from redemption of short-term investments	61,715	69,751	151,216
Purchase of other assets	-24,304	-35,322	-42,193
Change in restricted cash and cash equivalents	26,183	10,256	14,851
Net cash used in investing activities	-489,287	-862,381	-832,718
Cash flows from financing activities:	'	'	'
Net proceeds from issuance of preferred shares	218,449	393,544	0
Repurchase of preferred shares	-100,000	-404,073	0
Repurchase of common shares	-472,263	-317,687	-65,885
Dividends paid - common shares	-118,426	-120,487	-206,455
Dividends paid - preferred shares	-39,193	-38,228	-36,875
Proceeds from issuance of common shares	20,339	5,120	6,735
Sale of shares to noncontrolling interests	50,000	0	0
Net cash used in financing activities	-441,094	-481,811	-302,480
Effect of exchange rate changes on foreign currency cash and cash equivalents	-3,078	1,543	-2,610
Increase (decrease) in cash and cash equivalents	163,509	-222,032	52,334
Cash and cash equivalents - beginning of period	759,817	981,849	929,515
Cash and cash equivalents - end of period	923,326	759,817	981,849
Supplemental disclosures of cash flow information	'	'	'
Income taxes paid	22,472	10,897	23,853
Interest paid	$58,125	$58,125	$58,125

HISTORY

HISTORY	12 Months Ended
	Dec. 31, 2013
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
HISTORY [Text Block]	'
	AXIS Capital Holdings Limited (“AXIS Capital”) is the Bermuda-based holding company for the AXIS group of companies, collectively the “Company”. AXIS Capital was incorporated on December 9, 2002, under the laws of Bermuda. Through its subsidiaries and branches organized in Bermuda, the United States, Europe, Singapore, Canada, Australia and Latin America, AXIS Capital provides a broad range of (re)insurance products on a worldwide basis under two distinct global underwriting platforms, AXIS Insurance and AXIS Reinsurance. In these notes, the terms “we,” “us,” “our,” or the “Company” refer to AXIS Capital and its direct and indirect subsidiaries.

SIGNIFICANT_ACCOUNTING_POLICIE

SIGNIFICANT ACCOUNTING POLICIES	12 Months Ended
	Dec. 31, 2013
Accounting Policies [Abstract]	'
SIGNIFICANT ACCOUNTING POLICIES [Text Block]	'
	Basis of Presentation
	These consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States (“U.S. GAAP”) and include the accounts of AXIS Capital, its wholly-owned subsidiaries, and variable interest entities (“VIEs”) in which the Company is considered the primary beneficiary. All inter-company accounts and transactions have been eliminated.
	A VIE is an entity that either: (a) does not have equity investors with voting rights or (b) has equity investors that do not provide sufficient financial resources for the entity to support its activities. We are the primary beneficiary of a VIE if we have a controlling financial interest in the VIE, based on the following two characteristics: a) the power to direct the activities of the VIE that most significantly impact the economic performance of the VIE, and b) the obligation to absorb losses of the VIE that could potentially be significant to the VIE or the right to receive benefits from the VIE that could potentially be significant to the VIE.
	Tabular dollar and share amounts are in thousands, with the exception of per share amounts. All amounts are reported in U.S. dollars. To facilitate comparison of information across periods, certain reclassifications have been made to prior year amounts to conform to the current year's presentation.
	Use of Estimates
	The preparation of these consolidated financial statements requires management to make estimates and assumptions that affect the reported amount of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. While management believes that the amounts included in the consolidated financial statements reflect its best estimates and assumptions, actual results could differ from those estimates. The Company’s principal estimates include:
	•	reserve for losses and loss expenses;
	•	reinsurance recoverable on unpaid losses, including the provision for uncollectible amounts;
	•	gross and net premiums written and net premiums earned;
	•	other-than-temporary impairments (“OTTI”) in the carrying value of available-for-sale investment securities; and
	•	fair value measurements for our financial assets and liabilities.
	Our significant accounting policies are:
	a)	Investments
	Investments available for sale
	Our fixed maturities and equities classified as “available for sale” are reported at fair value at the balance sheet date. See Note 6 – Fair Value Measurements for additional information regarding the determination of fair value. The change in fair value (net unrealized gain or loss) on our available for sale investments, net of tax, is included as a separate component of accumulated other comprehensive income (loss) (“AOCI”) in shareholders’ equity.
	Net investment income includes interest and dividend income and the amortization of market premiums and discounts and is presented net of investment expenses. Investment income is recognized when earned. Purchases and sales of investments are recorded on a trade-date basis and realized gains/losses on sales of investments are determined based on the specific identification method.
	We recognize investment income from fixed maturities based on the constant effective yield method, which includes an adjustment for estimated principal repayments, if any. The effective yield used to determine the amortization for fixed maturities subject to prepayment risk (e.g. asset-backed, loan-backed and other structured securities) is recalculated and adjusted periodically based upon actual historical and/or projected future cash flows. The adjustments to the yield for highly-rated prepayable fixed maturities are accounted for using the retrospective method. The adjustments to the yield for other prepayable fixed maturities are accounted for using the prospective method.
	On a quarterly basis, we assess whether unrealized losses on available for sale investments represent impairments that are other than temporary. Several factors are considered in this assessment including, but not limited to: (i) the extent and duration of the decline, (ii) the reason for the decline (e.g. credit spread widening, credit event, foreign exchange rate movements), (iii) the historical and implied future volatility of the fair value, (iv) the financial condition and near-term prospects of the issuer and (v) the collateral structure and credit support of the security, if applicable.
	A fixed maturity is impaired when the fair value is below its amortized cost. For an impaired fixed maturity where we intend to sell the security or it is more likely than not that we will be required to sell the security before its anticipated recovery, the full amount of the impairment is charged to earnings and is included in net realized investment gains (losses). Where we intend to hold the impaired fixed maturity, we estimate the anticipated credit loss of the security and recognize only this portion of the impairment in earnings, with the remaining non-credit related balance of the impairment (i.e. related to interest rates, market conditions, etc.) recognized in AOCI.
	We impair an equity security in an unrealized loss position when we do not have the ability and intent to hold the security for a reasonable period of time to allow for a full recovery. The full impairment is charged to earnings and is included in net realized investment gains (losses).
	Upon recognition of an OTTI, the new cost basis for the security is the previous amortized cost for a fixed maturity or cost for an equity security less the OTTI recognized in earnings. The new cost basis is not adjusted for subsequent recoveries in fair value; except for fixed maturities whereby the difference between the new cost basis and the expected cash flows is accreted on a quarterly basis to net investment income over the remaining life of the fixed maturity.
	Other investments
	We record other investments at fair value (see Note 6 – Fair Value Measurements), with both changes in fair value and realized gains/losses reported in net investment income.
	Short-term investments
	Short-term investments primarily comprise highly-liquid debt securities with maturities greater than three months but less than one year from the date of purchase. These investments are carried at amortized cost, which approximates fair value.
	b)	Cash and cash equivalents
	Cash equivalents include money-market funds and fixed interest deposits placed with a maturity of under 90 days when purchased. Cash and cash equivalents are recorded at amortized cost, which approximates fair value due to the short-term, liquid nature of these securities. Our restricted cash balance primarily relates to funds held in trust in support of our obligations in regulatory jurisdictions where we operate as a non-admitted carrier.
	c)	Premiums and Acquisition Costs
	Premiums
	Insurance premiums written are recorded in accordance with the terms of the underlying policies. Reinsurance premiums are recorded at the inception of the contract and are estimated based upon information received from ceding companies. For multi-year contracts where (re)insurance premiums are payable in annual installments, premiums are recorded at the inception of the contract based on management’s best estimate of total premiums to be received. However, premiums are normally recognized on an annual basis for multi-year contracts where the cedant has the ability to unilaterally commute or cancel coverage within the term of the policy. The remaining annual premiums are included as written at each successive anniversary date within the multi-year term.
	Any subsequent differences arising on insurance and reinsurance premium estimates are recorded in the period they are determined.
	(Re)insurance premiums are earned evenly over the period during which we are exposed to the underlying risk, which is generally one to two years with the exception of multi-year contracts. Unearned premiums represent the portion of premiums written which is applicable to the unexpired risks under contracts in force.
	Reinstatement premiums are recognized and earned at the time a loss event occurs, where the coverage limits for the remaining life of the contract are reinstated under pre-defined contract terms. The accrual of reinstatement premiums is based on our estimate of losses and loss adjustment expenses, which reflects management’s judgment, as described in Note 2(d) – Losses and Loss Expenses below.
	Premiums receivable balances are reviewed for impairment at least quarterly and an allowance is established for amounts considered uncollectible. The need for charge-off of any amounts previously reserved as uncollectible is assessed on a quarterly basis.
	Acquisition Costs
	Acquisition costs vary with and are directly related to the acquisition of (re)insurance contracts and consist primarily of fees and commissions paid to brokers and premium taxes. Premiums receivable are presented net of applicable acquisition costs when contract terms provide for the right of offset. Acquisition costs are shown net of commissions earned on ceded reinsurance. Our net acquisition costs are deferred and charged to expense as the related premium is earned.
	Anticipated losses and loss expenses, other costs and investment income related to these premiums are considered in assessing the recoverability of our deferred acquisition costs. If deferred amounts are estimated to be unrecoverable, they are expensed. Compensation expenses for personnel involved in contract acquisition, as well as advertising costs, are expensed as incurred.
	d)	Losses and Loss Expenses
	Our reserve for losses and loss expenses represents an estimate of the unpaid portion of our ultimate liability for losses and loss expenses for (re)insured events that have occurred at or before the balance sheet date. The balance reflects both claims that have been reported to us (“case reserves”) and claims that have been incurred but not yet reported to us (“IBNR”). These amounts are reduced for estimated amounts of salvage and subrogation recoveries.
	We review our reserve for losses and loss expenses on a quarterly basis. Case reserves are primarily established based on amounts reported from insureds and/or their brokers. Management estimates IBNR after reviewing detailed actuarial analyses and applying informed judgment regarding qualitative factors that may not be fully captured in the actuarial estimates. A variety of actuarial methods are utilized in this process, including the Expected Loss Ratio, Bornhuetter-Ferguson and Chain Ladder methods. Our estimate is highly dependent on management’s judgment as to which method(s) are most appropriate for a particular accident year and class of business. Our historical claims data is often supplemented with industry benchmarks when applying these methodologies.
	Any adjustments to our previous reserve for losses and loss expenses estimates are recognized in the period they are determined. While we believe that our reserves for losses and loss expenses are adequate, this estimate requires significant judgment and new information, events or circumstances may result in ultimate losses that are materially greater or less than provided for in the Consolidated Balance Sheets.
	e)	Reinsurance
	In the normal course of business, we purchase reinsurance protection to limit our ultimate losses from catastrophic events and to reduce our loss aggregation risk. The premiums paid to our reinsurers (i.e. premiums ceded) are expensed over the coverage period. Prepaid reinsurance premiums represent the portion of premiums ceded applicable to the unexpired term of the contracts in force. Reinstatement-related premiums ceded are recorded at the time a loss event occurs and our coverage limits for the remaining life of a contract are reinstated under pre-defined contract terms; such premiums are expensed over the remaining risk period.
	Reinsurance recoverable related to our case reserves is estimated on a case-by-case basis by applying the terms of any applicable reinsurance coverage to our individual case reserve estimates. Our estimate of reinsurance recoverable related to our IBNR reserves is generally developed as part of our loss reserving process.
	Our reinsurance recoverable is presented net of a provision for uncollectible amounts, reflecting the amount we believe will ultimately not be recovered due to reinsurer insolvency, contractual disputes and/or some other reason. We apply case-specific provisions against certain recoveries that we deem unlikely to be collected in full. In addition, we use a default analysis to estimate our provision for uncollectible amounts on the remainder of the balance.
	The estimates of our reinsurance recoverable and the associated provision require management’s judgment and are reviewed in detail on a quarterly basis. Any adjustments to amounts recognized in prior periods are reported in our net losses and loss expenses in the Consolidated Statements of Operations for the period when the adjustments were identified. The charge-off of amounts previously reserved as uncollectible is also considered on a case-by-case basis as part of this quarterly process.
	f)	Foreign Exchange
	The Company’s reporting currency is the U.S. dollar. In translating the financial statements of our subsidiaries or branches where the functional currency is other than the U.S. dollar, assets and liabilities are converted into U.S. dollars using the rates of exchange in effect at the balance sheet dates and revenues and expenses are converted using the weighted average foreign exchange rates for the period. The effect of translation adjustments is reported as a separate component of AOCI in shareholders’ equity.
	In recording foreign currency transactions, revenue and expense items are converted to the relevant functional currency at the exchange rate prevailing at the transaction date. Assets and liabilities originating in currencies other than the functional currency are translated into the functional currency at the rates of exchange in effect at the balance sheet date. The resulting foreign currency gains or losses are recognized in the Consolidated Statements of Operations, with the exception of those related to foreign-denominated available for sale investments. For these investments, exchange rate fluctuations represent an unrealized appreciation/depreciation in the value of the securities and are included in the related component of AOCI.
	g)	Share-Based Compensation
	The Company is authorized to issue restricted stock awards and units, stock options and other equity-based awards to its employees and directors. The fair value of service-based awards is measured at the grant date, with the associated expense recognized on a straight-line basis over the service period. The fair value of performance-based awards ("PSUs") is measured at the grant date based on pre-established targets relating to certain performance based measures achieved by the Company, with the associated expense recognized on a straight-line basis over the applicable performance and vesting period. The compensation expense for PSUs is subject to a periodic review and adjustment taking into account actual performance of the Company. The fair value of the liability associated with cash-settled awards is re-measured at each balance sheet date, with the effects recognized as an increase or decrease to share-based compensation expense for the period. Forfeiture benefits are estimated at the time of grant and incorporated in the determination of share-based compensation expense.
	h)	Derivative Instruments
	Derivative Instruments not Designated as Hedging Instruments
	We may enter into derivative instruments such as futures, options, interest rate swaps and foreign currency forward contracts as part of our overall foreign currency risk management strategy, to obtain exposure to a particular financial market or for yield enhancement. During 2013, we began to write derivative based risk management products designed to address weather and commodity price risks, with the objective of generating profits on a portfolio basis. From time to time we may also enter into (re)insurance contracts that meet the FASB’s definition of a derivative contract.
	We measure all derivative instruments at fair value (see Note 6 – Fair Value Measurements) and recognize them as either assets or liabilities in the Consolidated Balance Sheets. Subsequent changes in fair value and any realized gains or losses are recognized in the Consolidated Statements of Operations.
	Derivative Instruments Designated as Hedging Instruments
	We may designate a currency derivative as a hedge of foreign exchange rate-related movements in the fair value of certain investment portfolios. This is referred to as a fair value hedge. Changes in the fair value of the designated fair value hedge, along with the changes in the fair value of the hedged asset attributable to the hedged risk, are recorded in net realized investment gains (losses) in the Consolidated Statements of Operations, along with any hedge ineffectiveness.
	To qualify for hedge accounting treatment, a derivative must be highly effective in mitigating the designated changes in value of the hedged item. Further, the hedge relationship must be designated and formally documented at the inception, detailing the particular risk management objective and strategy for the hedge, including the item and risk that is being hedged, the derivative that is being used, and how effectiveness will be assessed. We formally measure the hedge effectiveness at inception and on an ongoing basis. We evaluate the effectiveness on a retrospective and prospective basis, using the period-to-period dollar offset method. Using this method, if the hedge correlation is within the range of 80% to 125%, we consider the hedge effective and apply hedge accounting. Cash flows from derivative instruments designated as hedging instruments are presented as operating activities in the Consolidated Statements of Cash Flows.
	i)	Goodwill and Intangible Assets
	We classify intangible assets into three categories: (1) intangible assets with finite lives subject to amortization, (2) intangible assets with indefinite lives not subject to amortization, and (3) goodwill.
	We amortize intangible assets with finite lives over their estimated useful lives in proportion to the estimated economic benefits of the intangible assets. We also test these assets for impairment if circumstances indicate that the carrying value may not be fully recoverable. Such circumstances may include an economic downturn in a geographic market or a change in the assessment of future operations. If, as a result of such an evaluation, we determine that the carrying value of the finite-lived intangible assets is not recoverable, the value of the assets will be reduced to fair value with the difference being expensed in the Consolidated Statements of Operations.
	Our intangible assets with indefinite lives include licenses held by certain subsidiaries in various jurisdictions that allow such subsidiaries to write insurance and/or reinsurance business. These intangible assets are carried at or below estimated fair value and are tested annually for impairment, either qualitatively or quantitatively, and between annual tests if events or changes in circumstances indicate that it is more likely than not that the asset is impaired.
	We have recorded goodwill in connection with certain acquisitions. Goodwill represents the excess of the cost of acquisitions over the fair value of the net assets acquired and is assigned to applicable reporting unit(s) on the acquisition date, based upon the expected benefit to be received by the reporting unit. We determine the expected benefit based on several factors, including the purpose of the business combination, our strategy subsequent to the business combination and the structure of the acquired company subsequent to the business combination. Goodwill is not subject to amortization. We test goodwill for potential impairment during the fourth quarter each year and between annual tests if an event occurs or circumstances change that would more likely than not reduce the fair value of a reporting unit to a level below its carrying amount. We have the option to first make this assessment on a qualitative basis. Should we choose to forgo this option, or if our qualitative assessment indicates that fair value is more likely than not below carrying value, we conduct a quantitative two-step impairment evaluation at the reporting unit level. First, we identify potential impairment by comparing the estimated fair values of the reporting units to estimated book values, including goodwill. The fair value of each reporting unit is derived based upon valuation techniques and assumptions that we believe market participants would use to value our business. The estimated fair values are generally determined utilizing methodologies that incorporate discounted cash flow analyses. The values derived from the analyses are then compared to recent market transactions for reasonableness. We derive the net book value of our reporting units by estimating the amount of shareholders’ equity required to support the activities of each reporting unit. If the estimated fair value of a reporting unit exceeds the estimated book value, goodwill is not considered impaired. If the book value exceeds the estimated fair value, the second step compares the implied fair value of the reporting unit’s goodwill with the carrying amount of the goodwill in order to determine the magnitude of impairment to be recognized. The implied fair value of goodwill is determined by deducting the fair value of a reporting unit’s identifiable assets and liabilities from the fair value of the reporting unit as a whole. The excess of the carrying value of goodwill above the implied goodwill, if any, would be recognized as an impairment charge in the Consolidated Statements of Operations.
j)	Income Taxes
Certain subsidiaries and branches of the Company operate in jurisdictions where they are subject to taxation. Current and deferred income taxes are charged or credited to net income, or in certain cases to AOCI, based upon enacted tax laws and rates applicable in the relevant jurisdiction in the period in which the tax becomes accruable or realizable. Deferred income taxes are provided for all temporary differences between the bases of assets and liabilities used in the Consolidated Balance Sheets and those used in the various jurisdictional tax returns. When our assessment indicates that it is more likely than not that a portion of a deferred tax asset will not be realized in the foreseeable future, a valuation allowance against deferred tax assets is recorded. We recognize the tax benefits of uncertain tax positions only when the position is more-likely-than-not to be sustained upon audit by the relevant taxing authorities.
k)	Treasury Shares
Common shares repurchased by the Company and not subsequently cancelled are classified as treasury shares and are recorded at cost. This results in a reduction of shareholders’ equity in the Consolidated Balance Sheets. When shares are reissued from treasury, we use the average cost method to determine the cost of the reissued shares. Gains on sales/reissuances of treasury shares are credited to additional paid-in capital, while losses are charged to additional paid-in capital to the extent that previous net gains from reissued treasury shares were included therein; otherwise losses are charged to retained earnings.
l)	New Accounting Standards Adopted in 2013
Balance Sheet Offsetting
Effective January 1, 2013, we adopted Financial Accounting Standards Board ("FASB") guidance requiring additional disclosures about financial instruments and derivative instruments that are either: (1) offset for balance sheet presentation purposes or (2) subject to an enforceable master netting arrangement or similar arrangement, regardless of whether they are offset for balance sheet presentation purposes. The disclosure requirements of this guidance are limited to derivatives, repurchase agreements and reverse repurchase agreements, and securities borrowing/lending transactions. As this guidance is disclosure-related only and did not amend existing balance sheet offsetting guidance, adoption did not impact our results of operations, financial condition or liquidity. The additional disclosures are provided in Note 7 - Derivative Instruments.
Reporting Amounts Reclassified Out of Accumulated Other Comprehensive Income ("AOCI")
Effective January 1, 2013, we adopted FASB guidance requiring additional disclosures about reclassification adjustments from AOCI. As this guidance is disclosure-related only and did not amend existing guidance on the reporting of net income available to common shareholders or other comprehensive income, adoption did not impact our results of operations, financial condition or liquidity. The additional disclosures are provided in Note 19 - Other Comprehensive Income (Loss).

SEGMENT_INFORMATION

SEGMENT INFORMATION	12 Months Ended
	Dec. 31, 2013
Segment Reporting [Abstract]	'
SEGMENT INFORMATION [Text Block]	'
	Our underwriting operations are organized around our global underwriting platforms, AXIS Insurance and AXIS Reinsurance. Therefore we have determined that we have two reportable segments, insurance and reinsurance. We do not allocate our assets by segment, with the exception of goodwill and intangible assets, as we evaluate the underwriting results of each segment separately from the results of our investment portfolio.
	Insurance
	Our insurance segment provides insurance coverage on a worldwide basis. The product lines in this segment are property, marine, terrorism, aviation, credit and political risk, professional lines, liability and accident and health.
	Reinsurance
	Our reinsurance segment provides non-life treaty reinsurance to insurance companies on a worldwide basis. The product lines in this segment are catastrophe, property, professional lines, credit and surety, motor, liability, agriculture, engineering and other.
	The following tables summarize the underwriting results of our reportable segments, as well as the carrying values of allocated goodwill and intangible assets:
		At and year ended December 31, 2013	Insurance			Reinsurance			Total
		Gross premiums written	$	2,559,138		$	2,137,903		$	4,697,041
		Net premiums written	1,813,538			2,114,662			3,928,200
		Net premiums earned	1,722,762			1,984,303			3,707,065
		Other insurance related income	2,436			1,988			4,424
		Net losses and loss expenses	(1,050,402		)	(1,083,793		)	(2,134,195		)
		Acquisition costs	(242,363		)	(421,828		)	(664,191		)
		General and administrative expenses	(347,684		)	(137,450		)	(485,134		)
		Underwriting income	$	84,749		$	343,220		427,969
		Corporate expenses							(90,256		)
		Net investment income							409,312
		Net realized investment gains							75,564
		Foreign exchange losses							(26,143		)
		Interest expense and financing costs							(61,979		)
		Income before income taxes							$	734,467
		Net loss and loss expense ratio	61		%	54.6		%	57.6		%
		Acquisition cost ratio	14.1		%	21.3		%	17.9		%
		General and administrative expense ratio	20.1		%	6.9		%	15.5		%
		Combined ratio	95.2		%	82.8		%	91		%
		Goodwill and intangible assets	$	89,528		$	—		$	89,528
		At and year ended December 31, 2012	Insurance			Reinsurance			Total
		Gross premiums written	$	2,309,481		$	1,830,162		$	4,139,643
		Net premiums written	1,522,245			1,815,211			3,337,456
		Net premiums earned	1,558,058			1,857,405			3,415,463
		Other insurance related income	2,676			—			2,676
		Net losses and loss expenses	(953,564		)	(1,142,464		)	(2,096,028		)
		Acquisition costs	(226,859		)	(400,794		)	(627,653		)
		General and administrative expenses	(314,834		)	(116,487		)	(431,321		)
		Underwriting income	$	65,477		$	197,660		263,137
		Corporate expenses							(129,660		)
		Net investment income							380,957
		Net realized investment gains							127,469
		Foreign exchange losses							(29,512		)
		Interest expense and financing costs							(61,863		)
		Income before income taxes							$	550,528
		Net loss and loss expense ratio	61.2		%	61.5		%	61.4		%
		Acquisition cost ratio	14.6		%	21.6		%	18.4		%
		General and administrative expense ratio	20.2		%	6.3		%	16.4		%
		Combined ratio	96		%	89.4		%	96.2		%
		Goodwill and intangible assets	$	97,493		$	—		$	97,493
		At and year ended December 31, 2011	Insurance			Reinsurance			Total
		Gross premiums written	$	2,121,829		$	1,974,324		$	4,096,153
		Net premiums written	1,466,134			1,953,300			3,419,434
		Net premiums earned	1,429,687			1,885,274			3,314,961
		Other insurance related income	2,396			—			2,396
		Net losses and loss expenses	(919,319		)	(1,755,733		)	(2,675,052		)
		Acquisition costs	(199,583		)	(387,886		)	(587,469		)
		General and administrative expenses	(278,147		)	(103,915		)	(382,062		)
		Underwriting income (loss)	$	35,034		$	(362,260	)	(327,226		)
		Corporate expenses							(77,089		)
		Net investment income							362,430
		Net realized investment gains							121,439
		Foreign exchange gains							44,582
		Interest expense and financing costs							(62,598		)
		Income before income taxes							$	61,538
		Net loss and loss expense ratio	64.3		%	93.1		%	80.7		%
		Acquisition cost ratio	14		%	20.6		%	17.7		%
	General and administrative expense ratio	19.4		%	5.5		%	13.9		%
	Combined ratio	97.7		%	119.2		%	112.3		%
	Goodwill and intangible assets	$	99,590		$	—		$	99,590
The following table presents our gross premiums written by the geographical location of our subsidiaries:
	Year ended December 31,	2013			2012			2011
	Bermuda	$	718,904		$	684,588		$	822,237
	Europe	1,699,748			1,561,701			1,493,692
	United States	2,278,389			1,893,354			1,780,224
	Total gross premium written	$	4,697,041		$	4,139,643		$	4,096,153
The following table presents our net premiums earned by segment and line of business:
	Year ended December 31,	2013			2012			2011
	Insurance
	Property	$	462,364		$	408,943		$	385,291
	Marine	179,057			171,165			152,123
	Terrorism	39,298			38,605			35,213
	Aviation	48,489			60,363			70,681
	Credit and political risk	68,192			87,103			97,680
	Professional lines	586,200			563,500			536,238
	Liability	110,623			86,873			89,555
	Accident & health	228,539			141,506			62,906
	Total Insurance	1,722,762			1,558,058			1,429,687
	Reinsurance
	Catastrophe	380,199			375,088			456,858
	Property	350,970			351,470			356,022
	Professional lines	304,754			297,726			281,025
	Credit and surety	279,943			277,185			263,912
	Motor	221,844			237,006			202,830
	Liability	234,736			220,874			230,872
	Agriculture	126,490			17,116			15,031
	Engineering	66,243			68,402			65,727
	Other	19,124			12,538			12,997
	Total Reinsurance	1,984,303			1,857,405			1,885,274
	Total	$	3,707,065		$	3,415,463		$	3,314,961

GOODWILL_AND_INTANGIBLE_ASSETS

GOODWILL AND INTANGIBLE ASSETS	12 Months Ended
	Dec. 31, 2013
Goodwill and Intangible Assets Disclosure [Abstract]	'
GOODWILL AND INTANGIBLE ASSETS [Text Block]	'
	The following table shows an analysis of goodwill and intangible assets:
			Goodwill			Intangible		Intangible			Total
						assets with an		assets with a
						indefinite life		finite life
		Net balance at December 31, 2011	$	49,350		$	26,036	$	24,204		$	99,590
		Amortization	—			—		(2,618		)	(2,618		)
		Foreign currency translation adjustment	285			—		236			521
		Net balance at December 31, 2012	49,635			26,036		21,822			97,493
		Amortization	—			—		(2,233		)	(2,233		)
		Foreign currency translation adjustment	(3,213		)	—		(2,519		)	(5,732		)
		Net balance at December 31, 2013	$	46,422		$	26,036	$	17,070		$	89,528
		Gross balance at December 31, 2013	$	42,237		$	26,036	$	35,596		$	103,869
		Accumulated amortization	—			—		(23,601		)	(23,601		)
		Foreign currency translation adjustment	4,185			—		5,075			9,260
		Net balance at December 31, 2013	$	46,422		$	26,036	$	17,070		$	89,528
	We estimate that the annual amortization expense for our total intangible assets with a finite life will be approximately $2 million from 2014 to 2018. The estimated remaining useful lives of these assets range from six to twenty-five years.
	Intangible assets with an indefinite life consist primarily of U.S. state licenses that provide a legal right to transact business indefinitely. Our impairment reviews for goodwill and indefinite lived intangibles did not result in the recognition of impairment losses for the years ended December 31, 2013, 2012 and 2011.

INVESTMENTS

INVESTMENTS	12 Months Ended
	Dec. 31, 2013
Investments, Debt and Equity Securities [Abstract]	'
INVESTMENTS [Text Block]	'
	a)	Fixed Maturities and Equities
	The amortized cost or cost and fair values of our fixed maturities and equities were as follows:
			Amortized			Gross				Gross			Fair			Non-credit
			Cost or			Unrealized				Unrealized			Value			OTTI
			Cost			Gains				Losses						in AOCI(5)
		At December 31, 2013
		Fixed maturities
		U.S. government and agency	$	1,421,245		$	1,405			$	(33,952	)	$	1,388,698		$	—
		Non-U.S. government	1,208,384			17,990				(49,992		)	1,176,382			—
		Corporate debt	3,533,585			84,881				(10,228		)	3,608,238			—
		Agency RMBS(1)	2,485,139			21,979				(58,291		)	2,448,827			—
		CMBS(2)	790,095			11,285				(3,966		)	797,414			—
		Non-Agency RMBS	65,590			2,375				(398		)	67,567			(868		)
		ABS(3)	955,274			6,871				(8,694		)	953,451			—
		Municipals(4)	1,527,834			32,432				(14,516		)	1,545,750			—
		Total fixed maturities	$	11,987,146		$	179,218			$	(180,037	)	$	11,986,327		$	(868	)
		Equity securities
		Common stocks	345,759			98,742				(6,183		)	438,318
		Exchange-traded funds	106,762			32,085				—			138,847
		Non-U.S. bond mutual funds	113,698			11,124				—			124,822
		Total equity securities	$	566,219		$	141,951			$	(6,183	)	$	701,987
		At December 31, 2012
		Fixed maturities
		U.S. government and agency	$	1,413,520		$	9,484			$	(119	)	$	1,422,885		$	—
		Non-U.S. government	1,076,501			30,276				(2,201		)	1,104,576			—
		Corporate debt	3,746,616			135,658				(5,892		)	3,876,382			—
		Agency RMBS(1)	2,594,180			67,398				(1,670		)	2,659,908			—
		CMBS(2)	814,211			25,999				(126		)	840,084			—
		Non-Agency RMBS	93,266			2,503				(570		)	95,199			(884		)
		ABS(3)	639,614			10,774				(7,182		)	643,206			—
		Municipals(4)	1,227,764			58,770				(725		)	1,285,809			—
		Total fixed maturities	$	11,605,672		$	340,862			$	(18,485	)	$	11,928,049		$	(884	)
		Equity securities
		Common stocks	398,975			51,821				(7,398		)	443,398
		Exchange-traded funds	109,434			9,727				—			119,161
		Non-U.S. bond mutual funds	99,897			4,092				—			103,989
		Total equity securities	$	608,306		$	65,640			$	(7,398	)	$	666,548
	-1	Residential mortgage-backed securities (RMBS) originated by U.S. agencies.
	-2	Commercial mortgage-backed securities (CMBS).
	-3	Asset-backed securities (ABS) include debt tranched securities collateralized primarily by auto loans, student loans, credit cards, and other asset types. This asset class also includes collateralized loan obligations (CLOs) and collateralized debt obligations (CDOs).
	-4	Municipals include bonds issued by states, municipalities and political subdivisions.
	-5	Represents the non-credit component of the other-than-temporary impairment (OTTI) losses, adjusted for subsequent sales of securities. It does not include the change in fair value subsequent to the impairment measurement date.
	In the normal course of investing activities, we actively manage allocations to non-controlling tranches of structured securities (variable interests) issued by VIEs. These structured securities include RMBS, CMBS and ABS and are included in the above table. Additionally, within our other investments portfolio, we also invest in limited partnerships (hedge funds) and CLO equity tranched securities, which are all variable interests issued by VIEs (see Note 5(b)). For these variable interests, we do not have the power to direct the activities that are most significant to the economic performance of the VIEs and accordingly we are not the primary beneficiary for any of these VIEs. Our maximum exposure to loss on these interests is limited to the amount of our investment. We have not provided financial or other support with respect to these structured securities other than our original investment.
	Contractual Maturities
	The contractual maturities of fixed maturities are shown below. Expected maturities may differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties.
			Amortized			Fair				% of Total
			Cost			Value				Fair Value
		At December 31, 2013
		Maturity
		Due in one year or less	$	710,079		$	717,052			5.9	%
		Due after one year through five years	5,030,728			5,116,060				42.7	%
		Due after five years through ten years	1,852,877			1,791,835				14.9	%
		Due after ten years	97,364			94,121				0.8	%
			7,691,048			7,719,068				64.3	%
		Agency RMBS	2,485,139			2,448,827				20.4	%
		CMBS	790,095			797,414				6.7	%
		Non-Agency RMBS	65,590			67,567				0.6	%
		ABS	955,274			953,451				8	%
		Total	$	11,987,146		$	11,986,327			100	%
		At December 31, 2012
		Maturity
		Due in one year or less	$	651,111		$	657,045			5.5	%
		Due after one year through five years	4,880,039			4,989,151				41.8	%
	Due after five years through ten years	1,847,295			1,951,569				16.4	%
	Due after ten years	85,956			91,887				0.8	%
		7,464,401			7,689,652				64.5	%
	Agency RMBS	2,594,180			2,659,908				22.3	%
	CMBS	814,211			840,084				7	%
	Non-Agency RMBS	93,266			95,199				0.8	%
	ABS	639,614			643,206				5.4	%
	Total	$	11,605,672		$	11,928,049			100	%
Gross Unrealized Losses
The following table summarizes fixed maturities and equities in an unrealized loss position and the aggregate fair value and gross unrealized loss by length of time the security has continuously been in an unrealized loss position:
		12 months or greater							Less than 12 months						Total
		Fair			Unrealized				Fair			Unrealized			Fair			Unrealized
		Value			Losses				Value			Losses			Value			Losses
	At December 31, 2013
	Fixed maturities
	U.S. government and agency	$	—		$	—			$	982,307		$	(33,952	)	$	982,307		$	(33,952	)
	Non-U.S. government	35,577			(3,430		)		420,622			(46,562		)	456,199			(49,992		)
	Corporate debt	27,696			(802		)		606,592			(9,426		)	634,288			(10,228		)
	Agency RMBS	144,468			(5,247		)		1,478,527			(53,044		)	1,622,995			(58,291		)
	CMBS	13,319			(116		)		298,863			(3,850		)	312,182			(3,966		)
	Non-Agency RMBS	4,287			(315		)		5,319			(83		)	9,606			(398		)
	ABS	37,765			(2,941		)		553,803			(5,753		)	591,568			(8,694		)
	Municipals	8,408			(615		)		543,474			(13,901		)	551,882			(14,516		)
	Total fixed maturities	$	271,520		$	(13,466	)		$	4,889,507		$	(166,571	)	$	5,161,027		$	(180,037	)
	Equity securities
	Common stocks	$	3,499		$	(398	)		$	48,828		$	(5,785	)	$	52,327		$	(6,183	)
	Total equity securities	$	3,499		$	(398	)		$	48,828		$	(5,785	)	$	52,327		$	(6,183	)
	At December 31, 2012
	Fixed maturities
	U.S. government and agency	$	—		$	—			$	119,730		$	(119	)	$	119,730		$	(119	)
	Non-U.S. government	44,568			(1,453		)		153,134			(748		)	197,702			(2,201		)
	Corporate debt	95,511			(2,947		)		451,651			(2,945		)	547,162			(5,892		)
	Agency RMBS	9,557			(148		)		521,400			(1,522		)	530,957			(1,670		)
	CMBS	1,749			(16		)		69,615			(110		)	71,364			(126		)
	Non-Agency RMBS	11,026			(537		)		115			(33		)	11,141			(570		)
	ABS	99,514			(7,034		)		39,296			(148		)	138,810			(7,182		)
	Municipals	6,386			(270		)		77,766			(455		)	84,152			(725		)
	Total fixed maturities	$	268,311		$	(12,405	)		$	1,432,707		$	(6,080	)	$	1,701,018		$	(18,485	)
	Equity securities
	Common stocks	$	11,554		$	(1,793	)		$	95,697		$	(5,605	)	$	107,251		$	(7,398	)
	Total equity securities	$	11,554		$	(1,793	)		$	95,697		$	(5,605	)	$	107,251		$	(7,398	)
Fixed Maturities
At December 31, 2013, 1,127 fixed maturities (2012: 478) were in an unrealized loss position of $180 million (2012: $18 million) of which $2 million (2012: $3 million) was related to securities below investment grade or not rated.
At December 31, 2013, 99 securities (2012: 146) had been in a continuous unrealized loss position for 12 months or greater and had a fair value of $272 million (2012: $268 million). Following our credit impairment review, we concluded that these securities as well as the remaining securities in an unrealized loss position in the above table were temporarily depressed at December 31, 2013, and were expected to recover in value as the securities approach maturity. Further, at December 31, 2013, we did not intend to sell these securities in an unrealized loss position and it is more likely than not that we will not be required to sell these securities before the anticipated recovery of their amortized costs.
Equity Securities
At December 31, 2013, 63 securities (2012: 106) were in an unrealized loss position of $6 million (2012: $7 million).
At December 31, 2013, 9 (2012: 17) securities had been in a continuous unrealized loss position for 12 months or greater and had a fair value of $3 million (2012: $12 million). Based on our impairment review process and our ability and intent to hold these securities for a reasonable period of time sufficient for a full recovery, we concluded that the above equities in an unrealized loss position were temporarily impaired at December 31, 2013 and 2012.
b)	Other Investments
The following tables provide a breakdown of our investments in hedge funds, direct lending funds and CLO Equities, together with additional information relating to the liquidity of each category:
		Fair Value						Redemption Frequency		Redemption
								(if currently eligible)		Notice Period
	At December 31, 2013
	Long/short equity funds	$	425,444		41	%		Monthly, Quarterly, Semi-annually		30-60 days
	Multi-strategy funds	285,155			27	%		Quarterly, Semi-annually		60-95 days
	Event-driven funds	190,458			18	%		Quarterly, Annually		45-60 days
	Leveraged bank loan funds	48,753			5	%		Quarterly		65 days
	Direct lending funds	22,134			2	%		n/a		n/a
	CLO - Equities	73,866			7	%		n/a		n/a
	Total other investments	$	1,045,810		100	%
	At December 31, 2012
	Long/short equity funds	$	302,680		36	%		Monthly, Quarterly, Semi-annually		30-60 days
	Multi-strategy funds	244,075			29	%		Quarterly, Semi-annually		60-95 days
	Event-driven funds	171,479			20	%		Quarterly, Annually		45-95 days
	Leveraged bank loan funds	62,768			8	%		Quarterly		65 days
	Direct lending funds	—			—	%		n/a		n/a
	CLO - Equities	62,435			7	%		n/a		n/a
	Total other investments	$	843,437		100	%
n/a – not applicable
The investment strategies for the above funds are as follows:
•	Long/short equity funds: Seek to achieve attractive returns by executing an equity trading strategy involving both long and short investments in publicly-traded equities.
•	Multi-strategy funds: Seek to achieve above-market returns by pursuing multiple investment strategies to diversify risks and reduce volatility. This category includes funds of hedge funds which invest in a large pool of hedge funds across a diversified range of hedge fund strategies.
•	Event-driven funds: Seek to achieve attractive returns by exploiting situations where announced or anticipated events create opportunities.
•	Leveraged bank loan funds: Seek to achieve attractive returns by investing primarily in bank loan collateral that has limited interest rate risk exposure.
•	Direct lending funds: Seek to achieve attractive risk-adjusted returns, including current income generation, by investing in funds which provide financing directly to borrowers.
Two common redemption restrictions which may impact our ability to redeem our hedge funds are gates and lockups. A gate is a suspension of redemptions which may be implemented by the general partner or investment manager of the fund in order to defer, in whole or in part, the redemption request in the event the aggregate amount of redemption requests exceeds a predetermined percentage of the fund’s net assets which may otherwise hinder the general partner or investment manager’s ability to liquidate holdings in an orderly fashion in order to generate the cash necessary to fund extraordinarily large redemption payouts. A lockup period is the initial amount of time an investor is contractually required to hold the security before having the ability to redeem. During 2013 and 2012, neither of these restrictions impacted our redemption requests. At December 31, 2013, $99 million (2012: $38 million), representing 10% (2012: 5%) of our total hedge funds, relate to holdings where we are still within the lockup period. The expiry of this lockup periods range from April, 2014 to April, 2016.
At December 31, 2013, $11 million (2012: $29 million) was invested in hedge funds that are not accepting redemption requests. Of this amount, substantially all relates to a leveraged bank loan fund in a period of planned principal distributions. Based on market conditions and payments made to date, management's current expectation is that the distribution process will be completed in 2014. The remainder primarily relates to funds that entered liquidation or had their assets side pocketed as a result of the global financial crisis which began in late 2008. For these funds, management is currently unable to estimate when those funds will be distributed.
At December 31, 2013, we have $88 million (2012: $40 million) of unfunded commitments within our other investments portfolio relating to our future investments in direct lending funds. Once the full amount of committed capital has been called by the General Partner of each of these funds, the assets will not be fully returned until the completion of the fund's investment term. These funds have investment terms ranging from 5-10 years and the General Partners of certain funds have the option to extend the term by up to three years.
During 2013, we made a $60 million commitment as a limited partner in a multi-strategy hedge fund. Once the full amount of committed capital has been called by the General Partner, the assets will not be fully returned until the completion of the fund's investment term which ends in December, 2018. The General Partner then has the option to extend the term by up to three years. At December 31, 2013, $54 million of our commitment remains unfunded and the current fair value of the funds called to date are included in the multi-strategy funds line of the table above.
During 2013, we made a $60 million commitment as a limited partner in a fund that invests primarily in CLO equities ("CLO fund").  We will not be eligible to redeem our investment until December, 2017 but expect to receive interest distributions on a quarterly basis. At December 31, 2013, $27 million of our commitment remains unfunded and the current fair value of the funds called to date are included in the CLO - Equities line of the table above.  The CLO - Equities line also includes direct investment in the equity tranches of CLOs.
c)	Net Investment Income
Net investment income was derived from the following sources:
	Year ended December 31,	2013			2012				2011
	Fixed maturities	$	293,609		$	304,400			$	337,616
	Other investments	128,814			87,660				31,856
	Equity securities	10,897			11,904				11,186
	Cash and cash equivalents	6,337			4,528				5,697
	Short-term investments	1,181			596				1,592
	Gross investment income	440,838			409,088				387,947
	Investment expenses	(31,526		)	(28,131		)		(25,517		)
	Net investment income	$	409,312		$	380,957			$	362,430
d)	Net Realized Investment Gains
The following table provides an analysis of net realized investment gains:
	Year ended December 31,	2013			2012				2011
	Gross realized gains
	Fixed maturities and short-term investments(1)	$	120,932		$	242,082			$	243,296
	Equities	54,564			36,411				16,992
	Gross realized gains	175,496			278,493				260,288
	Gross realized losses
	Fixed maturities and short-term investments(1)	(87,894		)	(101,844		)		(108,490		)
	Equities	(10,407		)	(23,530		)		(14,526		)
	Gross realized losses	(98,301		)	(125,374		)		(123,016		)
	Net OTTI recognized in earnings	(9,362		)	(24,234		)		(15,861		)
	Change in fair value of investment derivatives(2)	7,731			(9,170		)		4,431
	Fair value hedges(2)	—			7,754				(4,403		)
	Net realized investment gains	$	75,564		$	127,469			$	121,439
-1	Includes $37 million of gains in 2012 and $11 million of losses in 2011 relating to previously unrealized foreign exchange currency amounts on the hedged fixed maturity portfolios. The hedged portfolio was sold and all associated foreign exchange contracts were fully settled during 2012 so there is no impact on the 2013 figures.
-2	Refer to Note 7 – Derivative Instruments
The following table summarizes the OTTI recognized in earnings by asset class:
	Year ended December 31,	2013			2012				2011
	Fixed maturities:
	Non-U.S. government	$	120		$	3,281			$	—
	Corporate debt	5,802			1,821				1,954
	Non-Agency RMBS	57			2,016				717
	ABS	129			795				61
	Municipals	639			—				483
		6,747			7,913				3,215
	Equity Securities
	Common stocks	2,092			7,318				12,646
	Exchange-traded funds	523			9,003				—
		2,615			16,321				12,646
	Total OTTI recognized in earnings	$	9,362		$	24,234			$	15,861
Fixed Maturities
The following table provides a roll forward of the credit losses (“credit loss table”), before income taxes, for which a portion of the OTTI was recognized in AOCI:
	Year ended December 31,	2013			2012
	Balance at beginning of period	$	1,809		$	2,061
	Credit impairments recognized on securities not previously impaired	—			—
	Additional credit impairments recognized on securities previously impaired	—			—
	Change in timing of future cash flows on securities previously impaired	—			—
	Intent to sell of securities previously impaired	—			—
	Securities sold/redeemed/matured	(215		)	(252		)
	Balance at end of period	$	1,594		$	1,809
Credit losses are calculated based on the difference between the amortized cost of the security and the net present value of its projected future cash flows discounted at the effective interest rate implicit in the debt security prior to the impairment. The following provides a summary of the credit loss activities by asset class for the above table as well as the significant inputs and the methodology used to estimate these credit losses.
U.S. Government, U.S. Agency and U.S. Agency RMBS:
Unrealized losses on securities issued or backed (either explicitly or implicitly) by the U.S. government are generally not analyzed for OTTI. We have concluded that the possibility of any credit losses on these securities is highly unlikely due to the explicit U.S. government guarantee on certain securities (e.g. GNMA issuances) and, on others, the implicit guarantee that has been validated by past actions (e.g. U.S. government bailout of FNMA and FHLMC during the 2008 credit crisis). Although not generally analyzed for credit losses, the securities are still evaluated for intention to sell at a loss.
Non-U.S. Government:
Non-U.S. government obligations are evaluated for credit loss primarily through qualitative assessments of the likelihood of credit loss using information such as duration and severity of unrealized losses, as well as credit ratings and price volatility. At December 31, 2013, our holdings in sovereign debt, including $161 million (2012: $217 million) relating to the eurozone countries, were substantially all investment-grade securities. The gross unrealized losses of $50 million at December 31, 2013 were mainly due to pricing and foreign exchange losses on emerging market debt. Based on our analysis, we do not anticipate any credit losses on our non-U.S. government fixed maturities at December 31, 2013.
Corporate Debt:
To estimate credit losses for corporate debt securities, our projected cash flows are primarily driven by our assumptions regarding the probability of default and the severity associated with those defaults. Our default and loss severity rates are based on credit rating, credit analysis, industry analyst reports and forecasts, Moody’s historical default data and any other data relevant to the recoverability of the security. In 2013, the OTTI charges on corporate debt securities were related to our intent to sell, as well as unrealized foreign exchange losses on certain securities where forecasted recovery was uncertain.
CMBS:
Our investments in CMBS are diversified and highly rated, with a weighted average estimated subordination percentage of 30% at December 31, 2013 (2012: 30%). Based on discounted cash flows at December 31, 2013, the current level of subordination is sufficient to cover the estimated loan losses on the underlying collateral of the CMBS.
Non-agency RMBS:
For non-agency RMBS, our projected cash flows incorporated underlying data from widely accepted third-party data sources along with certain internal assumptions and judgments regarding the future performance of the security. These assumptions included the following: default, delinquency, loss severity and prepayment rates. The assumptions used to calculate the credit losses in 2013 have not changed significantly since December 31, 2012. At December 31, 2013, the fair value of our non-agency RMBS was $68 million (2012: $95 million), consisting primarily of $41 million (2012: $65 million) of Prime and $19 million (2012: $22 million) of Alt-A MBS. We have concluded there are no credit losses anticipated for any of our non-agency RMBS at December 31, 2013, other than those already recorded.
ABS:
A significant portion of the unrealized losses on ABS at December 31, 2013, and 2012, were related to CLO debt tranched securities (“CLO Debt”) purchased prior to the credit crisis with a current carrying value of $30 million (2012: $53 million). We used the following significant inputs to estimate the credit loss for these securities:
	At December 31,	2013		2012
	Default rate	4.00%		4.00%
	Loss severity rate	53.50%		53.50%
	Collateral spreads	2.7% - 3.5%		2.5% - 3.7%
Our assumptions on default and loss severity rates are established based on an assessment of actual experience to date for each CLO Debt and review of recent credit rating agencies’ default and loss severity forecasts. Based on the underlying collateral values and our projected cash flows at December 31, 2013, we do not expect any credit losses on our CLO Debt as the current unrealized loss is reflective of the securities' low coupon relative to the higher market yields available for similar securities.
Equity Securities
The OTTI losses on common stocks in 2013 and 2012 are primarily due to the severity and duration of their unrealized loss positions, for which we concluded the forecasted recovery period was uncertain. The recognition of such losses does not necessarily indicate that sales will occur or that sales are imminent or planned. During 2013, we recorded $1 million (2012: $9 million) of OTTI losses on our exchange-traded funds as we no longer had the intent to hold these underwater securities through full recovery of cost. At December 31, 2013, the fair value of our equities was $702 million (2012: $667 million), which included $6 million (2012: $7 million) of gross unrealized losses.
e)	Restricted Investments
In order to support our obligations in regulatory jurisdictions where we operate as a non-admitted carrier, we provide collateral in the form of assets held in trust and, to a lesser extent, letters of credit. Refer to Note 10(b) for further information on our collateral requirements upon issuance of certain letters of credit. The fair value of our restricted investments primarily relates to these items, as noted in the table below. Our restricted investments primarily consist of high-quality fixed maturity and short-term investment securities.
	At December 31,		2013			2012
	Collateral in Trust for inter-company agreements		$	2,261,081		$	2,134,931
	Collateral for secured letter of credit facility		777,828			470,062
	Collateral in Trust for third party agreements		276,839			245,539
	Securities on deposit with regulatory authorities		58,327			59,456
	Total restricted investments		$	3,374,075		$	2,909,988
f)	Reverse Repurchase Agreements
At December 31, 2013, we held $34 million (2012: $39 million) of reverse repurchase agreements. These loans are fully collateralized, are generally outstanding for a short period of time and are presented on a gross basis as part of cash and cash equivalents on our consolidated balance sheet. The required collateral for these loans is either cash or U.S. Treasuries at a minimum rate of 102% of the loan principal. Upon maturity, we receive principal and interest income.

FAIR_VALUE_MEASUREMENTS

FAIR VALUE MEASUREMENTS	12 Months Ended
	Dec. 31, 2013
Fair Value Disclosures [Abstract]	'
FAIR VALUE MEASUREMENTS [Text Block]	'
	Fair Value Hierarchy
	Fair value is defined as the price to sell an asset or transfer a liability (i.e. the “exit price”) in an orderly transaction between market participants. We use a fair value hierarchy that gives the highest priority to quoted prices in active markets and the lowest priority to unobservable data. The hierarchy is broken down into three levels as follows:
	•	Level 1 - Valuations based on unadjusted quoted prices in active markets for identical assets or liabilities that we have the ability to access.
	•	Level 2 - Valuations based on quoted prices in active markets for similar assets or liabilities, quoted prices for identical assets or liabilities in inactive markets, or for which significant inputs are observable (e.g. interest rates, yield curves, prepayment speeds, default rates, loss severities, etc.) or can be corroborated by observable market data.
	•	Level 3 - Valuations based on inputs that are unobservable and significant to the overall fair value measurement. The unobservable inputs reflect our own judgments about assumptions that market participants might use.
	The availability of observable inputs can vary from financial instrument to financial instrument and is affected by a wide variety of factors including, for example, the type of financial instrument, whether the financial instrument is new and not yet established in the marketplace, and other characteristics particular to the transaction. To the extent that valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires significantly more judgment.
	Accordingly, the degree of judgment exercised by management in determining fair value is greatest for instruments categorized in Level 3. In periods of market dislocation, the observability of prices and inputs may be reduced for many instruments. This may lead us to change the selection of our valuation technique (from market to cash flow approach) or may cause us to use multiple valuation techniques to estimate the fair value of a financial instrument. This circumstance could cause an instrument to be reclassified between levels within the fair value hierarchy.
	We used the following valuation techniques and assumptions in estimating the fair value of our financial instruments as well as the general classification of such financial instruments pursuant to the above fair value hierarchy.
	Fixed Maturities
	At each valuation date, we use the market approach valuation technique to estimate the fair value of our fixed maturities portfolio, when possible. This market approach includes, but is not limited to, prices obtained from third party pricing services for identical or comparable securities and the use of “pricing matrix models” using observable market inputs such as yield curves, credit risks and spreads, measures of volatility, and prepayment speeds. Pricing from third party pricing services is sourced from multiple vendors, when available, and we maintain a vendor hierarchy by asset type based on historical pricing experience and vendor expertise. When prices are unavailable from pricing services, we obtain non-binding quotes from broker-dealers who are active in the corresponding markets.
	The following describes the significant inputs generally used to determine the fair value of our fixed maturities by asset class.
	U.S. government and agency
	U.S. government and agency securities consist primarily of bonds issued by the U.S. Treasury and mortgage pass-through agencies such as the Federal National Mortgage Association, the Federal Home Loan Mortgage Corporation and the Government National Mortgage Association. As the fair values of our U.S. Treasury securities are based on unadjusted market prices in active markets, they are classified within Level 1. The fair values of U.S. government agency securities are priced using the spread above the risk-free yield curve. As the yields for the risk-free yield curve and the spreads for these securities are observable market inputs, the fair values of U.S. government agency securities are classified within Level 2.
	Non-U.S. government
	Non-U.S. government securities comprise bonds issued by non-U.S. governments and their agencies along with supranational organizations (collectively also known as sovereign debt securities). The fair value of these securities is based on prices obtained from international indices or a valuation model that includes the following inputs: interest rate yield curves, cross-currency basis index spreads, and country credit spreads for structures similar to the sovereign bond in terms of issuer, maturity and seniority. As the significant inputs are observable market inputs, the fair value of non-U.S. government securities are classified within Level 2.
	Corporate debt
	Corporate debt securities consist primarily of investment-grade debt of a wide variety of corporate issuers and industries. The fair values of these securities are generally determined using the spread above the risk-free yield curve. These spreads are generally obtained from the new issue market, secondary trading and broker-dealer quotes. As these spreads and the yields for the risk-free yield curve are observable market inputs, the fair values of our corporate debt securities are classified within Level 2. Where pricing is unavailable from pricing services, we obtain non-binding quotes from broker-dealers to estimate fair value. This is generally the case when there is a low volume of trading activity and current transactions are not orderly. In this event, securities are classified within Level 3.
	MBS
	Our portfolio of RMBS and CMBS are originated by both agencies and non-agencies. The fair values of these securities are determined through the use of a pricing model (including Option Adjusted Spread) which uses prepayment speeds and spreads to determine the appropriate average life of the MBS. These spreads are generally obtained from the new issue market, secondary trading and broker-dealer quotes. As the significant inputs used to price MBS are observable market inputs, the fair values of the MBS are classified within Level 2. Where pricing is unavailable from pricing services, we obtain non-binding quotes from broker-dealers to estimate fair value. This is generally the case when there is a low volume of trading activity and current transactions are not orderly. These securities are classified within Level 3.
	ABS
	ABS include mostly investment-grade bonds backed by pools of loans with a variety of underlying collateral, including automobile loan receivables, student loans, credit card receivables, and CLO Debt originated by a variety of financial institutions. Similarly to MBS, the fair values of ABS are priced through the use of a model which uses prepayment speeds and spreads sourced primarily from the new issue market. As the significant inputs used to price ABS are observable market inputs, the fair values of ABS are classified within Level 2. Where pricing is unavailable from pricing services, we obtain non-binding quotes from broker-dealers or use a discounted cash flow model to estimate fair value. This is generally the case when there is a low volume of trading activity and current transactions are not orderly. These securities are priced within Level 3.
	Municipals
	Our municipal portfolio comprises revenue and general obligation bonds issued by U.S. domiciled state and municipal entities. The fair value of these securities is determined using spreads obtained from broker-dealers, trade prices and the new issue market. As the significant inputs used to price the municipals are observable market inputs, municipals are classified within Level 2.
	Equity Securities
	Equity securities include U.S. and non-U.S. common stocks, exchange-traded funds, and non-U.S. bond mutual funds. For common stocks and exchange-traded funds, we classified these within Level 1 as their fair values are based on unadjusted quoted market prices in active markets. Our investments in non-U.S. bond mutual funds have daily liquidity, with redemption based on the net asset value (NAV) of the funds. Accordingly, we have classified these investments as Level 2.
	Other Investments
	As a practical expedient, we estimate fair values for hedge funds, direct lending funds and the CLO fund using NAVs as advised by external fund managers or third party administrators. For each of these funds, the NAV is based on the manager's or administrator's valuation of the underlying holdings in accordance with the fund's governing documents and in accordance with U.S. GAAP. For any funds for which we have not yet received a NAV concurrent with our period end date, we record an estimate of the change in fair value for the period subsequent to the most recent NAV. Such estimates are based on return estimates for the period between the most recently issued NAV and the period end date; these estimates are obtained from the relevant fund managers. Accordingly, we do not typically have a reporting lag in our fair value measurements for these funds. Historically, our valuation estimates incorporating these return estimates have not significantly diverged from the subsequent NAVs.
	Within the hedge fund, direct lending fund and CLO fund industries, there is a general lack of transparency necessary to facilitate a detailed independent assessment of the values placed on the securities underlying the NAV provided by the fund manager or fund administrator. To address this, on a quarterly basis, we perform a number of monitoring procedures designed to assist us in the assessment of the quality of the information provided by managers and administrators. These procedures include, but are not limited to, regular review and discussion of each fund's performance with its manager, regular evaluation of fund performance against applicable benchmarks and the backtesting of our fair value estimates against subsequently received NAVs. Backtesting involves comparing our previously reported values for each individual fund against NAVs per audited financial statements (for year-end values) and final NAVs from fund managers and fund administrators (for interim values).
	For our hedge fund investments with liquidity terms allowing us to fully redeem our holdings at the applicable NAV in the near term, we have classified these investments as Level 2. Certain investments in hedge funds, all of our direct lending funds and our CLO fund have redemption restrictions (see Note 5(b) for further details) that prevent us from redeeming in the near term and therefore we have classified these investments as Level 3.
	At December 31, 2013, our direct investments in CLO - Equities were classified within Level 3 as we estimated the fair value for these securities using an income approach valuation technique (discounted cash flow model) due to the lack of observable and relevant trades in the secondary markets.
	Short-Term Investments
	Short-term investments primarily comprise highly liquid securities with maturities greater than three months but less than one year from the date of purchase. These securities are classified within Level 2 because these securities are typically not actively traded due to their approaching maturity and, as such, their amortized cost approximates fair value.
	Derivative Instruments
	Our foreign currency forward contracts and interest rate swaps are customized to our economic hedging strategies and trade in the over-the-counter derivative market. We use the market approach valuation technique to estimate the fair value for these derivatives based on significant observable market inputs from third party pricing vendors, non-binding broker-dealer quotes and/or recent trading activity. Accordingly, we classified these derivatives within Level 2.
	We also participate in non-exchange traded derivative-based risk management products addressing weather risks. We use observable market inputs and unobservable inputs in combination with industry or internally-developed valuation and forecasting techniques to determine fair value. We classify these instruments within Level 3.
	Cash Settled Awards
	Cash settled awards comprise restricted stock units that form part of our compensation program. Although the fair value of these awards is determined using observable quoted market prices in active markets, the stock units themselves are not actively traded. Accordingly, we have classified these liabilities within Level 2.
	The table below presents the financial instruments measured at fair value on a recurring basis:
			Quoted Prices in			Significant			Significant			Total Fair
			Active Markets for			Other Observable			Unobservable			Value
			Identical Assets			Inputs			Inputs
			(Level 1)			(Level 2)			(Level 3)
		At December 31, 2013
		Assets
		Fixed maturities
		U.S. government and agency	$	1,119,632		$	269,066		$	—		$	1,388,698
		Non-U.S. government	—			1,176,382			—			1,176,382
		Corporate debt	—			3,608,238			—			3,608,238
		Agency RMBS	—			2,448,827			—			2,448,827
		CMBS	—			793,396			4,018			797,414
		Non-Agency RMBS	—			67,567			—			67,567
		ABS	—			922,652			30,799			953,451
		Municipals	—			1,545,750			—			1,545,750
			1,119,632			10,831,878			34,817			11,986,327
		Equity securities
		Common stocks	438,318			—			—			438,318
		Exchange-traded funds	138,847			—			—			138,847
		Non-U.S. bond mutual funds	—			124,822			—			124,822
			577,165			124,822			—			701,987
		Other investments
		Hedge funds	—			488,755			461,055			949,810
		Direct lending funds	—			—			22,134			22,134
		CLO-Equities	—			—			73,866			73,866
		—			488,755			557,055			1,045,810
	Short-term investments	—			46,212			—			46,212
	Derivative instruments (see Note 7)	—			6,824			984			7,808
	Total Assets	$	1,696,797		$	11,498,491		$	592,856		$	13,788,144
	Liabilities
	Derivative instruments (see Note 7)	$	—		$	1,152		$	815		$	1,967
	Cash settled awards (see Note 16)	—			8,693			—			8,693
	Total Liabilities	$	—		$	9,845		$	815		$	10,660
	At December 31, 2012
	Assets
	Fixed maturities
	U.S. government and agency	$	1,094,220		$	328,665		$	—		$	1,422,885
	Non-U.S. government	—			1,104,576			—			1,104,576
	Corporate debt	—			3,874,832			1,550			3,876,382
	Agency RMBS	—			2,659,908			—			2,659,908
	CMBS	—			835,788			4,296			840,084
	Non-Agency RMBS	—			94,089			1,110			95,199
	ABS	—			579,231			63,975			643,206
	Municipals	—			1,285,809			—			1,285,809
		1,094,220			10,762,898			70,931			11,928,049
	Equity securities
	Common stocks	443,398			—			—			443,398
	Exchange-traded funds	119,161			—			—			119,161
	Non-U.S. bond mutual funds	—			103,989			—			103,989
		562,559			103,989			—			666,548
	Other investments
	Hedge funds	—			421,006			359,996			781,002
	Direct lending funds	—			—			—			—
	CLO-Equities	—			—			62,435			62,435
		—			421,006			422,431			843,437
	Short-term investments	—			108,860			—			108,860
	Derivative instruments (see Note 7)	—			5,838			—			5,838
	Total Assets	$	1,656,779		$	11,402,591		$	493,362		$	13,552,732
	Liabilities
	Derivative instruments (see Note 7)	$	—		$	3,737		$	—		$	3,737
	Cash settled awards (see Note 16)	—			—			—			—
	Total Liabilities	$	—		$	3,737		$	—		$	3,737
During 2013 and 2012, we had no transfers between Levels 1 and 2.
Level 3 Fair Value Measurements
Except for hedge funds, direct lending funds and our CLO fund priced using NAV as a practical expedient and certain fixed maturities priced using broker-dealer quotes (underlying inputs are not available), the following table quantifies the significant unobservable inputs we have used in estimating fair value at December 31, 2013 for our investments classified as Level 3 in the fair value hierarchy. These significant unobservable inputs have not changed significantly from December 31, 2012. Where appropriate, this table has been reconciled back to the asset class' total Level 3 holdings.
		Fair Value		Valuation Technique	Unobservable Input	Range	Weighted
							Average
	ABS - CLO Debt	$	29,944	Discounted cash flow	Credit spreads	3.3% - 4.6%	3.70%
					Illiquidity discount (1)	5%	5%
		855		Broker-dealer quote	n/a	n/a	n/a
		$	30,799
	Other investments - CLO Equities	$	39,706	Discounted cash flow	Default rates	4.0% - 5.0%	4.40%
					Loss severity rate	53.50%	53.50%
					Collateral spreads	2.6% - 3.4%	3.30%
					Estimated maturity dates	2.1 - 4.6 years	4.2 years
		34,160		Net asset value	n/a	n/a	n/a
		$	73,866
	Derivatives - Weather derivatives, net	$	169	Simulation model	Weather curve	525 - 4,750(2)	n/a (3)
					Weather standard deviation	94 - 290(2)	n/a (3)
(1) Judgmentally determined based on limited trades of similar securities observed in the secondary markets.
(2) Measured in Heating Degree Days ("HDD") which is the number of degrees the daily temperature is below a reference temperature. The cumulative HDD for the duration of the derivatives contract is compared to the strike value to determine the necessary settlement.
-3	Due to the diversity of the portfolio, the range of unobservable inputs is widespread; therefore, presentation of a weighted average is not useful. Weather parameters may include various temperature and/or precipitation measures that will naturally vary by geographic location of each counterparty's operations.
Our CLO Debt represent holdings of investment-grade debt tranches within collateralized loan obligations with underlying collateral of loans originated primarily by U.S. corporations. The CLO Debt in the table represent securities where broker-dealer quotes are unavailable so we estimate fair value through the use of a discounted cash flow model (income approach). This model estimates fair values by discounting the estimated cash flows based on current credit spreads for similar securities, derived from observable offer prices. As these securities are thinly traded in the secondary market, we apply an illiquidity discount to these discounted cash flows in developing our estimate of fair value. Significant increases (decreases) in either of the significant unobservable inputs (credit spread, illiquidity discount) in isolation would result in lower (higher) fair value estimates for our CLO Debt. The interrelationship between these inputs is insignificant. These inputs are updated on a quarterly basis and the reasonableness of the resulting prices is assessed through a comparison to observable offer prices for similar securities.
The CLO - Equities market continues to be mostly inactive with only a small number of transactions being observed in the market and fewer still involving transactions in our CLO - Equities. Accordingly, we continue to rely on the use of our internal discounted cash flow model (income approach) to estimate fair value of our direct investments in CLO - Equities. Of the significant inputs into this model, the default and loss severity rates are the most judgmental unobservable market inputs to which the valuation of CLO - Equities is most sensitive. A significant increase (decrease) in either of these significant inputs in isolation would result in lower (higher) fair value estimates for direct investments in our CLO - Equities and, in general, a change in default rate assumptions will be accompanied by a directionally similar change in loss severity rate assumptions. Collateral spreads and estimated maturity dates are less judgmental inputs as they are based on the historical average of actual spreads and the weighted average life of the current underlying portfolios, respectively.  A significant increase (decrease) in either of these significant inputs in isolation would result in higher (lower) fair value estimates for direct investments in our CLO - Equities.  In general, these inputs have no significant interrelationship with each other or with default and loss severity rates.
On a quarterly basis, our valuation processes for both CLO Debt and CLO - Equities include a review of the underlying cash flows and key assumptions used in the discounted cash flow models. We review and update the above significant unobservable inputs based on information obtained from secondary markets, including from the managers of the CLOs we hold. These inputs are the responsibility of management and, in order to ensure fair value measurement is applied consistently and in accordance with U.S. GAAP, we update our assumptions through regular communication with industry participants and ongoing monitoring of the deals in which we participate (e.g. default and loss severity rate trends), we maintain a current understanding of the market conditions, historical results, as well as emerging trends that may impact future cash flows. By maintaining this current understanding, we are able to assess the reasonableness of the inputs we ultimately use in our models.
Weather derivatives relate to non-exchange traded risk management products addressing weather risks. We use observable market inputs and unobservable inputs in combination with industry or internally-developed simulation models to determine fair value; these models may reference market price information for similar instruments. The pricing models are internally reviewed by Risk Management personnel prior to implementation and are reviewed periodically thereafter.
Observable and unobservable inputs to these models vary by contract type and would typically include the following:
•	Observable inputs: market prices for similar instruments, notional, option strike, term to expiry, contractual limits;
•	Unobservable inputs: correlation; and
•	Both observable and unobservable inputs: weather curves, weather standard deviation.
In general, weather curves are the most significant contributing input to fair value determination; changes in this variable can result in result in higher or lower fair value depending on the underlying position. In addition, changes in any or all of the unobservable inputs identified above may contribute positively or negatively to overall portfolio value. The correlation input will quantify the interrelationship, if any, amongst the other variables.
The following tables present changes in Level 3 for financial instruments measured at fair value on a recurring basis for the periods indicated:
		Opening			Transfers			Transfers			Included in			Included			Purchases			Sales			Settlements/			Closing		Change in
		Balance			into			out of			earnings (1)			in OCI (2)									Distributions			Balance		unrealized
					Level 3			Level 3																				investment
																												gain/loss (3)
	Year ended December 31, 2013
	Fixed maturities
	Corporate debt	$	1,550		$	—		$	—		$	1,550		$	—		$	—		$	—		$	(3,100	)	$	—	$	—
	Non-Agency RMBS	1,110			—			(1,222		)	—			135			—			—			(23		)	—		—
	CMBS	4,296			—			—			—			(278		)	—			—			—			4,018		—
	ABS	63,975			—			—			(111		)	1,794			—			—			(34,859		)	30,799		—
		70,931			—			(1,222		)	1,439			1,651			—			—			(37,982		)	34,817		—
	Other investments
	Hedge funds	359,996			—			—			58,293			—			86,138			—			(43,372		)	461,055		58,293
	Direct lending funds	—			—			—			(125		)	—			22,317			—			(58		)	22,134		(125		)
	CLO-Equities	62,435			—			—			27,898			—			34,016			—			(50,483		)	73,866		27,898
		422,431			—			—			86,066			—			142,471			—			(93,913		)	557,055		86,066
	Other assets
	Derivative instruments	—			—			—			2,084			—			(1,100		)	—			—			984		2,084
		—			—			—			2,084			—			(1,100		)	—			—			984		2,084
	Total assets	$	493,362		$	—		$	(1,222	)	$	89,589		$	1,651		$	141,371		$	—		$	(131,895	)	$	592,856	$	88,150
	Other liabilities
	Derivative instruments	—			—			—			98			—			717			—			—			815		98
	Total liabilities	$	—		$	—		$	—		$	98		$	—		$	717		$	—		$	—		$	815	$	98
	Year ended December 31, 2012
	Fixed maturities
	Corporate debt	$	1,550		$	—		$	—		$	—		$	—		$	—		$	—		$	—		$	1,550	$	—
	Non-Agency RMBS	—			1,110			—			—			—			—			—			—			1,110		—
	CMBS	—			4,296			—			—			—			—			—			—			4,296		—
	ABS	49,328			10,539			—			—			5,112			—			—			(1,004		)	63,975		—
		50,878			15,945			—			—			5,112			—			—			(1,004		)	70,931		—
	Other investments
	Hedge funds	346,244			—			(9,435		)	33,301			—			—			(2,835		)	(7,279		)	359,996		33,301
	Direct lending funds	—			—			—			—			—			—			—			—			—		—
	CLO-Equities	66,560			—			—			31,108			—			—			—			(35,233		)	62,435		31,108
		412,804			—			(9,435		)	64,409			—			—			(2,835		)	(42,512		)	422,431		64,409
	Other assets
	Derivative instruments	—			—			—			—			—			—			—			—			—		—
		—			—			—			—			—			—			—			—			—		—
	Total assets	$	463,682		$	15,945		$	(9,435	)	$	64,409		$	5,112		$	—		$	(2,835	)	$	(43,516	)	$	493,362	$	64,409
	Other liabilities
	Derivative instruments	—			—			—			—			—			—			—			—			—		—
	Total liabilities	$	—		$	—		$	—		$	—		$	—		$	—		$	—		$	—		$	—	$	—
-1	Gains and losses included in earnings on fixed maturities are included in net realized investment gains (losses). Gains and (losses) included in earnings on other investments are included in net investment income. Gains (losses) on weather derivatives included in earnings are included in other insurance-related income.
-2	Gains and losses included in other comprehensive income (“OCI”) on fixed maturities are included in unrealized gains (losses) arising during the period.
-3	Change in unrealized investment gain/(loss) relating to assets held at the reporting date.
The transfers into and out of fair value hierarchy levels reflect the fair value of the securities at the end of the reporting period.
Transfers into Level 3 from Level 2
The transfers to Level 3 from Level 2 made during 2012 were primarily due to the lack of observable market inputs and multiple quotes from pricing vendors and broker-dealers for certain fixed maturities. No such transfers were made during 2013.
Transfers out of Level 3 into Level 2
The transfers from Level 3 to Level 2 made during 2013 were primarily due to the availability of observable market inputs and multiple quotes from pricing vendors and broker-dealers. The transfer from Level 3 to Level 2 in 2012 related to certain hedge funds where we had the ability to liquidate holdings at the reported NAV in the near term due to the expiry of lockup provisions.
Financial Instruments Not Carried at Fair Value
U.S. GAAP guidance over disclosures about the fair value of financial instruments are also applicable to financial instruments not carried at fair value, except for certain financial instruments, including insurance contracts.
The carrying values of cash equivalents (including restricted amounts), accrued investment income, receivable for investments sold, certain other assets, payable for investments purchased and certain other liabilities approximated their fair values at December 31, 2013, due to their respective short maturities. As these financial instruments are not actively traded, their respective fair values are classified within Level 2.
At December 31, 2013, our senior notes are recorded at amortized cost with a carrying value of $996 million (2012: $995 million) and have a fair value of $1,073 million (2012: $1,091 million). The fair values of these securities were obtained from a third party pricing service and pricing was based on the spread above the risk-free yield curve. These spreads are generally obtained from the new issue market, secondary trading and broker-dealer quotes. As these spreads and the yields for the risk-free yield curve are observable market inputs, the fair values of our senior notes are classified within Level 2.

DERIVATIVE_INSTRUMENTS

DERIVATIVE INSTRUMENTS	12 Months Ended
	Dec. 31, 2013
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
DERIVATIVE INSTRUMENTS [Text Block]	'
	The following table summarizes the balance sheet classification of derivatives recorded at fair value. The notional amount of derivative contracts represents the basis upon which pay or receive amounts are calculated and is presented in the table to quantify the volume of our derivative activities. Notional amounts are not reflective of credit risk.
			At December 31, 2013												At December 31, 2012
			Derivative				Asset				Liability				Derivative				Asset		Liability
			Notional				Derivative				Derivative				Notional				Derivative		Derivative
			Amount				Fair				Fair				Amount				Fair		Fair
							Value(1)				Value(1)								Value(1)		Value(1)
		Derivatives not designated as hedging instruments
		Relating to investment portfolio:
		Foreign exchange forward contracts	$	254,023			1,214				1,032				$	287,819			1,067		2,733
		Interest rate swaps	281,250				873				—				—				—		—
		Relating to underwriting portfolio:
		Foreign exchange forward contracts	390,663				4,737				120				476,191				4,771		1,004
		Weather-related contracts	24,451				984				815				—				—		—
		Total derivatives					$	7,808			$	1,967							$	5,838	$	3,737
	-1	Asset and liability derivatives are classified within other assets and other liabilities on the Consolidated Balance Sheets.
	Offsetting Assets and Liabilities
	Our derivative instruments are generally traded under International Swaps and Derivatives Association master netting agreements, which establish terms that apply to all transactions. In the event of a bankruptcy or other stipulated event, master netting agreements provide that individual positions be replaced with a new amount, usually referred to as the termination amount, determined by taking into account market prices and converting into a single currency. Effectively, this contractual close-out netting reduces credit exposure from gross to net exposure. The table below presents a reconciliation of our gross derivative assets and liabilities to the net amounts presented in our Consolidated Balance Sheets, with the difference being attributable to the impact of master netting agreements.
			December 31, 2013										December 31, 2012
			Gross Amounts			Gross Amounts Offset			Net				Gross Amounts			Gross Amounts Offset			Net
									Amounts(1)										Amounts(1)
		Derivative assets	$	9,796		$	(1,988	)	$	7,808			$	6,476		$	(639	)	$	5,838
		Derivative liabilities	3,955			(1,988		)	1,967				4,376			(639		)	3,737
	-1	Net asset and liability derivatives are classified within other assets and other liabilities on the Consolidated Balance Sheets.
	Refer to Note 5 - Investments for information on reverse repurchase agreements.
	Fair Value Hedges
	During 2012, we sold all available for sale fixed maturities in the portfolios that qualified for hedge accounting and settled all of the associated foreign exchange forward contracts. The hedges were designated and qualified as fair value hedges, resulting in the net impact of the hedges recognized in net realized investment gains (losses).
	The following table provides the total impact on earnings of applying hedge accounting for foreign exchange contracts designated as fair value hedges along with the impact of the related hedged investment portfolio for the periods indicated:
		Year ended December 31,	2013				2012				2011
		Foreign exchange forward contracts	$	—			$	10,853			$	11,682
		Hedged investment portfolio	—				(3,099		)		(16,085		)
		Hedge ineffectiveness recognized in earnings	$	—			$	7,754			$	(4,403	)
	Derivative Instruments not Designated as Hedging Instruments
	a) Relating to Investment Portfolio
	Foreign Currency Risk
	Within our investment portfolio we are exposed to foreign currency risk. Accordingly, the fair values for our investment portfolio are partially influenced by the change in foreign exchange rates. We may enter into foreign currency forward contracts to manage the effect of this foreign currency risk. These foreign currency hedging activities are not designated as specific hedges for financial reporting purposes.
	In addition, our external equity investment managers have the discretion to hold foreign currency exposures as part of their total return strategy.
	Interest Rate Risk
	Our investment portfolio contains a large percentage of fixed maturities which exposes us to significant interest rate risk. As part of our overall management of this risk, we may use interest rate swaps. The interest rate swaps held at December 31, 2013 convert part of our overall fixed rate exposure to a variable rate exposure which effectively reduces the duration of our overall portfolio.
	b) Relating to Underwriting Portfolio
	Foreign Currency Risk
	Our (re)insurance subsidiaries and branches operate in various foreign countries. Consequently, some of our business is written in currencies other than the U.S. dollar and, therefore, our underwriting portfolio is exposed to significant foreign currency risk. We manage foreign currency risk by seeking to match our foreign-denominated net liabilities under (re)insurance contracts with cash and investments that are denominated in such currencies. We may also use derivative instruments, specifically forward contracts and currency options, to economically hedge foreign currency exposures.
	Weather Risk
	During 2013, we began to write derivative-based risk management products designed to address weather risks with the objective of generating profits on a portfolio basis. The majority of this business consists of receiving a payment at contract inception in exchange for bearing the risk of variations in a quantifiable weather-related phenomenon, such as temperature. Where a client wishes to minimize the upfront payment, these transactions may be structured as swaps or collars. In general, our portfolio of such derivative contracts is of short duration, with contracts being predominantly seasonal in nature. In order to economically hedge a portion of this portfolio, we may also purchase weather derivatives.
	The total unrealized and realized gains (losses) recognized in earnings for derivatives not designated as hedges were as follows:
			Location of Gain (Loss) Recognized	Amount of Gain (Loss) Recognized  in
			in Income on Derivative	Income on Derivative
				2013				2012				2011
		Derivatives not designated as hedging instruments
		Relating to investment portfolio:
		Foreign exchange forward contracts	Net realized investment gains	$	10,843			$	(9,170	)		$	4,431
		Interest rate swaps	Net realized investment gains	(3,112		)		—				—
		Relating to underwriting portfolio:
		Foreign exchange forward contracts	Foreign exchange gains (losses)	1,690				26,612				33,893
		Currency collar options	Foreign exchange gains (losses)	—				—				267
		Weather-related contracts	Other insurance related income	1,987				—				—
		Total		$	11,408			$	17,442			$	38,591

RESERVE_FOR_LOSSES_AND_LOSS_EX

RESERVE FOR LOSSES AND LOSS EXPENSES	12 Months Ended
	Dec. 31, 2013
Insurance Loss Reserves [Abstract]	'
RESERVE FOR LOSSES AND LOSS EXPENSES [Text Block]	'
	Our reserve for losses and loss expenses comprise the following:
		As of December 31,	2013			2012
		Reserve for reported losses and loss expenses	$	3,499,817		$	3,272,682
		Reserve for losses incurred but not reported	6,082,323			5,786,049
		Reserve for losses and loss expenses	$	9,582,140		$	9,058,731
	The following table presents a reconciliation of our beginning and ending gross reserve for losses and loss expenses and net reserve for unpaid losses and loss expenses for the periods indicated:
		Year ended December 31,	2013			2012			2011
		Gross reserve for losses and loss expenses, beginning of period	$	9,058,731		$	8,425,045		$	7,032,375
		Less reinsurance recoverable on unpaid losses, beginning of period	(1,825,617		)	(1,736,823		)	(1,540,633		)
		Net reserve for unpaid losses and loss expenses, beginning of period	7,233,114			6,688,222			5,491,742
		Net incurred losses and loss expenses related to:
		Current year	2,353,631			2,340,868			2,932,513
		Prior years	(219,436		)	(244,840		)	(257,461		)
			2,134,195			2,096,028			2,675,052
		Net paid losses and loss expenses related to:
		Current year	(318,006		)	(322,836		)	(509,075		)
		Prior years	(1,373,459		)	(1,299,384		)	(953,035		)
			(1,691,465		)	(1,622,220		)	(1,462,110		)
		Foreign exchange and other	6,184			71,084			(16,462		)
		Net reserve for unpaid losses and loss expenses, end of period	7,682,028			7,233,114			6,688,222
		Reinsurance recoverable on unpaid losses, end of period	1,900,112			1,825,617			1,736,823
		Gross reserve for losses and loss expenses, end of period	$	9,582,140		$	9,058,731		$	8,425,045
	We write business with loss experience generally characterized as low frequency and high severity in nature, which can result in volatility in our financial results. During 2013, 2012 and 2011, respectively, we recognized aggregate net losses and loss expenses of $201 million, $438 million and $944 million in relation to natural catastrophe and weather-related events.
	Prior year reserve development arises from changes to loss and loss expense estimates related to loss events that occurred in previous calendar years. Such development is summarized by segment in the following table:
			Insurance			Reinsurance			Total
		Year ended December 31, 2013	$	50,355		$	169,081		$	219,436
		Year ended December 31, 2012	122,209			122,631			244,840
		Year ended December 31, 2011	103,014			154,447			257,461
	Overall, the majority of the net favorable prior year reserve development related to short-tail lines of business. Net favorable prior year reserve development for liability reinsurance also contributed significantly in 2013 with professional lines contributing notably in 2012 and 2011. Favorable development in 2013 was partially offset by adverse development in the insurance professional lines.
	The underlying exposures in our property, marine and aviation reserving classes within our insurance segment and the property reserving class within our reinsurance segment largely relate to short-tail business. Development from these classes contributed $162 million, $186 million and $178 million of the total net favorable prior year reserve development in 2013, 2012 and 2011, respectively, and primarily reflected the recognition of better than expected loss emergence.
	In the first quarter of 2013, we began to give weight to actuarial methods that reflect our actual experience for liability reinsurance business, as we believe that our older accident years are now at a stage of expected development where such methods will produce meaningful actuarial indications. During 2013, we recognized $85 million of net favorable prior year development, primarily reflecting the greater weight management is giving to experience based indications and our experience which has been favorable for the 2004 through 2008 accident years.
	Our professional lines business recognized $29 million of net adverse development in 2013. This increase in the reserves was due to a $51 million adverse development in the insurance segment, reflecting worse than expected loss experience for the 2011-2012 accident years, due to worse than expected loss experience on certain parts of our U.S. D&O business, and the 2008-2009 accident years, due to developments on certain global financial crisis-related claims. Comparably in 2012 and 2011 professional lines contributed net favorable prior year reserve developments of $54 million and $105 million, respectively. The 2012 and 2011 favorable prior year reserve developments were driven by increased weight being given to experience-based actuarial methods in selecting our ultimate loss estimates for accident years 2009 and prior. During 2013, the transition to the experience-based actuarial methods also had a favorable impact on 2009 and prior years, which partially offset the adverse development discussed above.
	The frequency and severity of natural catastrophe and weather activity was high in recent years and our December 31, 2013 net reserve for losses and loss expenses continues to include estimated amounts for numerous events. We caution that the magnitude and/or complexity of losses arising from certain of these events, in particular Storm Sandy, the Japanese earthquake and tsunami and the three New Zealand earthquakes, inherently increase the level of uncertainty and, therefore, the level of management judgment involved in arriving at our estimated net reserves for losses and loss expenses. As a result, our actual losses for these events may ultimately differ materially from our current estimates.

REINSURANCE

REINSURANCE	12 Months Ended
	Dec. 31, 2013
Reinsurance Disclosures [Abstract]	'
REINSURANCE [Text Block]	'
	We purchase treaty and facultative reinsurance to reduce exposure to significant losses. Facultative reinsurance provides coverage for all or a portion of the losses incurred for a single policy and we separately negotiate each facultative contract. Treaty reinsurance provides coverage for a specified type or category of risks. Our treaty reinsurance agreements provide this coverage on either an excess of loss or a proportional basis. Excess of loss covers provide a contractually set amount of coverage after a specified loss amount has been reached. These covers can be purchased on a package policy basis, which provide us with coverage for a number of lines of business within one contract. In contrast, proportional covers provide us with a specified percentage of coverage from the first dollar of loss.
	All of these reinsurance covers provide us the right to recover of a portion of specified losses and loss expenses from reinsurers. However, to the extent that our reinsurers do not meet their obligations under these agreements due to solvency issues, contractual disputes or other reasons, we remain liable. We predominantly cede our business to reinsurers rated A- or better by A.M. Best.
	Gross and net premiums written and earned were as follows:
		Year ended December 31,	2013						2012						2011
			Premiums			Premiums			Premiums			Premiums			Premiums			Premiums
			written			earned			written			earned			written			earned
		Gross	$	4,697,041		$	4,459,269		$	4,139,643		$	4,141,037		$	4,096,153		$	3,973,956
		Ceded	(768,841		)	(752,204		)	(802,187		)	(725,574		)	(676,719		)	(658,995		)
		Net	$	3,928,200		$	3,707,065		$	3,337,456		$	3,415,463		$	3,419,434		$	3,314,961
	During the year ended December 31, 2013, we recognized ceded losses and loss expenses of $415 million (2012: $396 million; 2011: $450 million).
	Our provision for unrecoverable reinsurance was $18 million at December 31, 2013 (2012: $16 million). At December 31, 2013, 98.8% (2012: 98.8%) of our gross reinsurance recoverables were collectible from reinsurers rated A- or better by A.M. Best.

DEBT_AND_FINANCING_ARRANGEMENT

DEBT AND FINANCING ARRANGEMENTS	12 Months Ended
	Dec. 31, 2013
Debt Disclosure [Abstract]	'
DEBT AND FINANCING ARRANGEMENTS [Text Block]	'
	a)	Senior Notes
	On November 15, 2004, AXIS Capital issued $500 million aggregate principal amount of 5.75% senior unsecured debt (the “5.75% Senior Notes”) at an issue price of 99.785%, generating net proceeds of $496 million. Interest on the 5.75% Senior Notes is payable semi-annually in arrears on June 1 and December 1 of each year, beginning on June 1, 2005. Unless previously redeemed, the 5.75% Senior Notes will mature on December 1, 2014.
	On March 23, 2010, AXIS Specialty Finance LLC (“AXIS Specialty Finance”), a 100% owned finance subsidiary, issued $500 million aggregate principal amount of 5.875% senior unsecured debt (the “5.875% Senior Notes” and, together with the 5.75% Senior Notes, the “Senior Notes”) at an issue price of 99.624%. The net proceeds of the issuance, after consideration of the offering discount and underwriting expenses and commissions, totaled approximately $495 million. Interest on the 5.875% Senior Notes is payable semi-annually in arrears on June 1 and December 1 of each year, beginning on June 1, 2010. Unless previously redeemed, the 5.875% Senior Notes will mature on June 1, 2020. The 5.875% Senior Notes are ranked as unsecured senior obligations of AXIS Specialty Finance. AXIS Capital has fully and unconditionally guaranteed all obligations of AXIS Specialty Finance under the 5.875% Senior Notes. AXIS Capital’s obligations under this guarantee are unsecured and senior and rank equally with all other senior obligations of AXIS Capital.
	We have the option to redeem the Senior Notes at any time and from time to time, in whole or in part, at a “make-whole” redemption price, which is equal to the greater of the aggregate principal amount or the sum of the present values of the remaining scheduled payments of principal and interest. The related indentures contain various covenants, including limitations on liens on the stock of restricted subsidiaries, restrictions as to the disposition of the stock of restricted subsidiaries and limitations on mergers and consolidations. We were in compliance with all the covenants contained in the indentures at December 31, 2013.
	Interest expense recognized in relation to our Senior Notes includes interest payable, amortization of the offering discounts and amortization of debt offering expenses. The offering discounts and debt offering expenses are amortized over the period of time during which the Senior Notes are outstanding. During 2013, we incurred interest expense of $59 million (2012: $59 million, 2011: $59 million).
	b)	Credit Facilities
	On March 26, 2013, in advance of the scheduled August expiration, we terminated and replaced our previously existing credit facility. AXIS Capital and certain subsidiaries are now party to a $250 million credit facility (the "Credit Facility"), which was issued by a syndication of lenders pursuant to a Credit Agreement and other ancillary documents (together, the "Facility Documents") and will expire in March 2017. At the request of the Company and subject to the satisfaction of certain conditions, the aggregate commitment available under the Credit Facility may be increased by up to $150 million. Under the terms of the Credit Facility, loans are available for general corporate purposes and letters of credit may be issued in the ordinary course of business, with total usage not to exceed the aggregate commitment available. Interest on loans issued under the Credit Facility is payable based on underlying market rates at the time of loan issuance. While loans under the Credit Facility are unsecured, we have the option to issue letters of credit on a secured basis in order to reduce associated fees. Letters of credit issued under the Credit Facility would principally be used to support the (re)insurance obligations of our operating subsidiaries. Each of AXIS Capital, AXIS Specialty Finance and AXIS Specialty Holdings Bermuda Limited guarantees the obligations of the other parties to the Credit Facility. The Credit Facility is subject to certain non-financial covenants, including limitations on fundamental changes, the incurrence of additional indebtedness and liens and certain transactions with affiliates and investments, as defined in the Facility Documents. The Credit Facility also requires compliance with certain financial covenants, including a maximum debt to capital ratio and a minimum consolidated net worth requirement. In addition, each of AXIS Capital’s material (re)insurance subsidiaries party to the Credit Facility must maintain a minimum A.M. Best Company, Inc. financial strength rating. In the event of default, including a breach of these covenants, the lenders may exercise certain remedies including the termination of the Credit Facility, the declaration of all principal and interest amounts related to Credit Facility loans to be immediately due and the requirement that all outstanding letters of credit be collateralized.
	On September 18, 2013, we entered into an amendment to the Credit Facility in order to permit AXIS Capital and its subsidiaries to enter into swap contracts and other arrangements related to weather derivative transactions. All other material terms and conditions remained unchanged.
	On November 6, 2013, AXIS Capital's subsidiary, AXIS Specialty Limited, entered into a $170 million secured letter of credit facility (the "Lloyd's LOC Facility") with ING Bank N.V., London Branch ("ING") pursuant to a Letter of Credit Facility Agreement and Security Agreement (collectively, the "Lloyd's Facility Documents"). The Lloyd's LOC Facility is fully utilized and meets the Funds at Lloyd's requirements for the Company's subsidiary, AXIS Corporate Capital UK Limited to support the underwriting capacity of the Company's Lloyd's syndicate, AXIS Syndicate 1686, for the 2014 underwriting year of account. The Letter of Credit issued under the Lloyd's LOC Facility will expire no later than July 31, 2018. The Lloyd's Facility Documents contain customary covenants with which the Company must comply, including a requirement to maintain sufficient collateral to fully secure any issued Letter of Credit. In case of an event of default under the Lloyd's Facility Documents, ING may exercise certain remedies, including the exercise of sole and exclusive control over pledged collateral.
	On November 20, 2013, certain of AXIS Capital’s operating subsidiaries entered into an amendment to extend the term of the Company's secured $750 million letter of credit facility (the “LOC Facility”) with Citibank Europe plc (“Citibank”) pursuant to a Master Reimbursement Agreement and other ancillary documents (together, the “LOC Facility Documents”). The LOC Facility may be terminated by Citibank on December 31, 2016 upon thirty days prior notice. Under the terms of the LOC Facility, letters of credit to a maximum aggregate amount of $750 million are available for issuance on behalf of the operating subsidiaries. These letters of credit will principally be used to support the reinsurance obligations of the operating subsidiaries. The LOC Facility is subject to certain covenants, including the requirement to maintain sufficient collateral, as defined in the LOC Facility Documents, to cover all of the obligations under the LOC Facility. Such obligations include contingent reimbursement obligations for outstanding letters of credit and fees payable to Citibank. In the event of default, Citibank may exercise certain remedies, including the exercise of control over pledged collateral and the termination of the availability of the LOC Facility to any or all of the operating subsidiaries party to the LOC Facility Documents.
	At December 31, 2013, we had $501 million, $170 million and nil letters of credit outstanding under the LOC Facility, Lloyd's LOC Facility and the Credit Facility, respectively. There was no debt outstanding under the Credit Facility. We were in compliance with all LOC Facility, Lloyd's LOC Facility and Credit Facility covenants at December 31, 2013.

COMMITMENTS_AND_CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	12 Months Ended
	Dec. 31, 2013
Commitments and Contingencies Disclosure [Abstract]	'
COMMITMENTS AND CONTINGENCIES [Text Block]	'
	a)	Concentrations of Credit Risk
	Credit Risk Aggregation
	We monitor and control the aggregation of credit risk on a consolidated basis by assigning limits on the maximum credit exposure we are willing to assume by single obligors and groups, industry sector, country, region or other inter-dependencies. Our credit exposures are aggregated based on the origin of risk. Limits are based and adjusted on a variety of factors, including the prevailing economic environment and the nature of the underlying credit exposures. Our credit aggregation measurement and reporting process is facilitated by an exposure database, which contains relevant information on counterparties and credit risk; we also license third party databases to provide credit risk assessments.
	Credit risk aggregation is also managed through minimizing overlaps in underwriting, financing and investing activities.
	The assets that potentially subject us to concentrations of credit risk consist principally of cash and investments, reinsurance recoverable and (re)insurance premiums receivable balances, as described below:
	Cash and Investments
	In order to mitigate concentration and operational risks related to cash and cash equivalents, we limit the maximum amount of cash that can be deposited with a single counterparty and additionally limit acceptable counterparties based on current rating, outlook and other relevant factors.
	Our investment portfolio is managed by external investment managers in accordance with our investment guidelines. We limit credit risk through diversification, issuer exposure limitation graded by ratings and, with respect to custodians, through contractual and other legal remedies. Excluding U.S. government and agency securities, we limit our concentration of credit risk to any single corporate issuer to 2% or less of our fixed maturities portfolio for securities rated A- or above and 1% or less of our fixed maturities portfolio for securities rated below A-. At December 31, 2013, we were in compliance with these limits.
	Reinsurance Recoverable Balances
	With respect to our reinsurance recoverable balances, we are exposed to the risk of a reinsurer failing to meet its obligations under coverage we have purchased. To mitigate this risk, all reinsurance coverage we purchase is subject to requirements established by our Reinsurance Security Committee. This Committee maintains a list of approved reinsurers, performs credit risk assessments for potential new reinsurers, regularly monitors approved reinsurers with consideration for events which may have a material impact on their creditworthiness, recommends counterparty tolerance levels for different types of ceded business and monitors concentrations of credit risk. The assessment of each reinsurer considers a range of attributes, including a review of financial strength, industry position and other qualitative factors. Generally, the Committee requires that reinsurers who do not meet specified requirements provide collateral.
	The three largest balances by reinsurer accounted for 14%, 11% and 11% of total reinsurance recoverable on unpaid and paid losses at December 31, 2013 (2012: 13%, 10% and 10%). Amounts related to our reinsurers with the ten largest balances comprised 77% of December 31, 2013 balance (2012: 72%) and had a weighted average A.M. Best rating of A+ (2012: A+).
	Premiums Receivable Balances
	The diversity of our client base limits the credit risk associated with our premiums receivable. In addition, for insurance contracts we have contractual rights to cancel coverage for non-payment of premiums and for reinsurance contracts we have contractual rights to offset premiums receivable with corresponding payments for losses and loss expenses.
	Brokers and other intermediaries collect premiums from customers to be paid to us. We have policies and standards in place to manage and monitor credit risk from intermediaries with a focus on day-to-day monitoring of the largest positions.
	These contractual rights contribute to the mitigation of credit risk, as does our monitoring of aged receivable balances. In light of these mitigating factors, and considering that a significant portion of our premiums receivable are not currently due based on the terms of the underlying contracts, we do not utilize specific credit quality indicators to monitor our premiums receivable balance. At December 31, 2013, we recorded an allowance for estimated uncollectible premiums receivable of $3 million (2012: $2 million). The corresponding bad debts expense charges for 2013, 2012 and 2011 were insignificant.
	b)	Brokers
	We produce our business through brokers and direct relationships with insurance companies. During 2013, three brokers accounted for 61% (2012: 61%; 2011: 63%) of our total gross premiums written. Aon Corporation accounted for 26% (2012: 27%; 2011: 27%), Marsh, Inc. (including its subsidiary Guy Carpenter and Company) for 23% (2012: 22%; 2011: 23%), and Willis Group Holdings Ltd. for 12% (2012: 12%; 2011: 13%). No other broker and no one insured or reinsured accounted for more than 10% of our gross premiums written in any of the last three years.
	c)	Lease Commitments
	We lease office space under operating leases which expire at various dates. We renew and enter into new leases in the ordinary course of business, as required. During 2013, total rent expense with respect to these operating leases was $29 million (2012: $29 million; 2011: $24 million).
	Future minimum lease payments under our leases are expected to be as follows:
		Year ended December 31,
		2014	$	31,207
		2015	27,378
		2016	23,838
		2017	20,881
		2018	17,955
		Later years	53,049
		Total future minimum lease payments	$	174,308
	d)	Reinsurance Purchase Commitment
	We purchase reinsurance coverage for our insurance lines of business. The minimum reinsurance premiums are contractually due in advance on a quarterly basis. Accordingly at December 31, 2013, we have an outstanding reinsurance purchase commitment of $80 million. Actual payments under the reinsurance contracts will depend on the underlying subject premium and may exceed the minimum premium.
	e)	Legal Proceedings
	From time to time, we are subject to routine legal proceedings, including arbitrations, arising in the ordinary course of business. These legal proceedings generally relate to claims asserted by or against us in the ordinary course of insurance or reinsurance operations; estimated amounts payable under such proceedings are included in the reserve for losses and loss expenses in our Consolidated Balance Sheets.
	We are not party to any material legal proceedings arising outside the ordinary course of business.

EARNINGS_PER_COMMON_SHARE

EARNINGS PER COMMON SHARE	12 Months Ended
	Dec. 31, 2013
Earnings Per Share [Abstract]	'
EARNINGS PER COMMON SHARE [Text Block]	'
	The following table sets forth the comparison of basic and diluted earnings per common share:
		At and year ended December 31,	2013		2012		2011
		Basic earnings per common share
		Net income	$	727,465	$	547,241	$	46,305
		Less: preferred share dividends	40,474		38,228		36,875
		Less: loss on repurchase of preferred shares	3,081		14,009		—
		Net income available to common shareholders	683,910		495,004		9,430
		Weighted average common shares outstanding - basic	113,636		122,148		122,499
		Basic earnings per common share	$	6.02	$	4.05	$	0.08
		Diluted earnings per common share
		Net income available to common shareholders	$	683,910	$	495,004	$	9,430
		Weighted average common shares outstanding - basic	113,636		122,148		122,499
		Warrants	—		—		4,292
		Stock compensation plans	1,692		1,506		1,331
		Weighted average common shares outstanding - diluted	115,328		123,654		128,122
		Diluted earnings per common share	$	5.93	$	4	$	0.07
		Anti-dilutive shares excluded from the dilutive computation	250		614		1,134

SHAREHOLDERS_EQUITY

SHAREHOLDERS' EQUITY	12 Months Ended
	Dec. 31, 2013
Stockholders' Equity Note [Abstract]	'
SHAREHOLDERS' EQUITY [Text Block]	'
	a)	Common Shares
	At December 31, 2013, and 2012, our authorized share capital was 800,000,000 common shares, par value of $0.0125 per share.
	The following table presents our common shares issued and outstanding, excluding restricted shares under our stock compensation plans (see Note 16 – Share-based Compensation):
		Year ended December 31,	2013		2012			2011
		Shares issued, balance at beginning of period	171,867		170,159			154,912
		Shares issued	2,267		1,708			15,247
		Total shares issued at end of period	174,134		171,867			170,159
		Treasury shares, balance at beginning of period	(53,947	)	(44,571	)		(42,519	)
		Shares repurchased	(10,830	)	(9,376	)		(2,052	)
		Shares reissued from treasury	128		—			—
		Total treasury shares at end of period	(64,649	)	(53,947	)		(44,571	)
		Total shares outstanding	109,485		117,920			125,588
	During 2013, the total cash dividends declared per common share were $1.02 (2012: $0.97; 2011: $0.93).
	Warrants
	During 2011, our founding shareholders exercised all remaining warrants. These warrants were exercised on a cashless basis pursuant to the terms of the applicable warrant agreements, resulting in a lower number of shares being issued than the number of warrants exercised. Accordingly, we issued 12,893,483 common shares upon the exercise of 19,827,760 warrants. In connection with the warrant exercise, we paid deferred dividends of $93 million to those warrant holders who chose the deferred cash option for dividends declared.
	Treasury shares
	On December 9, 2013, our Board of Directors authorized a new share repurchase plan for up to $750 million of our common shares through December 31, 2015. The new plan is effective January 1, 2014.
	The following table presents our common share repurchase activities, which are held in treasury:
		Year ended December 31,	2013			2012				2011
		In the open market:
		Total shares	7,362			6,057				1,609
		Total cost	$	337,083		$	203,704			$	49,974
		Average price per share(2)	$	45.79		$	33.63			$	31.07
		From employees:(1)
		Total shares	468			319				443
		Total cost	$	19,080		$	10,483			$	15,911
		Average price per share(2)	$	40.75		$	32.85			$	35.92
		From founding shareholder:(3)
		Total shares	3,000			3,000				—
		Total cost	$	116,100		$	103,500			$	—
		Average price per share(2)	$	38.7		$	34.5			$	—
		Total
		Total shares	10,830			9,376				2,052
		Total cost	$	472,263		$	317,687			$	65,885
		Average price per share(2)	$	43.61		$	33.88			$	32.11
	-1	To satisfy withholding tax liabilities upon vesting of restricted stock, restricted stock units, and exercise of stock options. Share repurchases from employees are excluded from the authorized share repurchase plans noted above.
	-2	Calculated using whole figures.
	-3	We privately negotiated with Trident II, L.P. and affiliated entities to repurchase 3,000,000 (2012: 3,000,000; 2011: none) of our common shares.
	b)	Preferred Shares
	Series A Preferred Shares
	During October 2005, we issued $250 million of 7.25% Series A preferred shares, par value $0.0125 per share, with a liquidation preference of $25.00 per share. In 2012, concurrent with the issuance of our Series C preferred shares (see below), we redeemed 6,000,000 of the 7.25% Series A preferred shares, representing $150 million in aggregate liquidation preference, without accumulation of any undeclared dividends. In connection with this redemption, we recognized a $5 million loss on redemption (calculated as the difference between the redemption price and the carrying value), which was recognized as a reduction in determining our net income available to common shareholders.
	During June 2013, we redeemed the remaining 4,000,000 Series A preferred shares outstanding, representing an aggregate liquidation preference of $100 million. In connection with this redemption, we recognized a $3 million loss.
	For 2013, the total dividends declared on Series A preferred shares were $0.9063 per share. In 2013, dividends of $1.3594 per share were paid, of which $0.4531 had been declared in 2012. For 2012 and 2011, the total dividends declared and paid on Series A preferred shares were $1.8125 per share.
	Series B Preferred Shares
	During November 2005, we issued $250 million of 7.50% Series B preferred shares, par value $0.0125 per share, with a liquidation preference of $100.00 per share. We may redeem the shares on or after December 1, 2015 at a redemption price of $100.00 per share. Dividends on the Series B preferred shares if, as and when declared by our board of directors will be payable initially at a fixed rate per annum equal to 7.50% of the liquidation preference on the first day of March, June, September and December of each year, commencing on March 1, 2006, up to but not including December 1, 2015. Commencing on March 1, 2016, the dividend rate on the Series B preferred shares will be payable at a floating rate. During a floating rate period, the floating rate per annum will be reset quarterly at a rate equal to 3.4525% plus the 3 month LIBOR Rate. Dividends on the Series B preferred shares are non-cumulative.
	During April 2012, we closed a cash tender offer for any and all of our outstanding 7.50% Series B preferred shares at a purchase price of $102.81 per share. As a result, we purchased 2,471,570 Series B preferred shares for $254 million. In connection with this tender offer, we recognized a $9 million loss on redemption (calculated as the difference between the redemption price and the carrying value), which was recognized as a reduction in determining our net income available to common shareholders. Following the completion of the tender offer, 28,430 Series B preferred shares, representing $3 million in aggregate liquidation preference, remain outstanding.
	For 2013, 2012 and 2011, total dividends declared and paid on Series B preferred shares were $7.50 per share.
	Series C Preferred Shares
	During March 2012, we issued $400 million of 6.875% Series C preferred shares, par value $0.0125 per share, with a liquidation preference of $25.00 per share. We may redeem the Series C preferred shares on or after April 15, 2017 at a redemption price of $25.00 per share. Dividends on the Series C preferred shares are non-cumulative. Consequently, if the board of directors does not authorize and declare a dividend for any period, holders of the Series C preferred shares will not be entitled to receive a dividend for such period, and such undeclared dividend will not accumulate and be payable. Holders of the Series C preferred shares will be entitled to receive, only when, as and if declared by the board of directors, non-cumulative cash dividends from the original issue date, quarterly in arrears on the fifteenth day of January, April, July and October of each year, commencing on July 15, 2012, without accumulation of any undeclared dividends. To the extent declared, these dividends will accumulate, with respect to each dividend period, in an amount per share equal to 6.875% of the liquidation preference per annum.
	For 2013 the total dividends declared and paid on Series C preferred shares were $1.7188 per share. For 2012, the total dividends declared on Series C preferred shares were $1.4132 per share. Of this amount, $0.9835 was paid in 2012 and the remaining $0.4297 was subsequently paid in 2013.
	Series D Preferred Shares
	During May 2013, we issued $225 million of 5.50% Series D preferred shares, par value $0.0125 per share, with a liquidation preference of $25.00 per share. We may redeem the Series D preferred shares on or after June 1, 2018 at a redemption price of $25.00 per share. Dividends on the Series D preferred shares are non-cumulative. Consequently, if the Board of Directors does not authorize and declare a dividend for any period, holders of the Series D preferred shares will not be entitled to receive a dividend for such period, and such undeclared dividend will not accumulate and be payable. Holders of the Series D preferred shares will be entitled to receive, only when, as and if declared by the Board of Directors, non-cumulative cash dividends from the original issue date, quarterly in arrears on the first day of March, June, September and December of each year, commencing on September 1, 2013, without accumulation of any undeclared dividends. To the extent declared, these dividends will accumulate, with respect to each dividend period, in an amount per share equal to 5.50% of the liquidation preference per annum.
	For 2013, the total dividends declared on Series D preferred shares were $0.6875 per share. Of this amount, $0.3438 was paid in 2013 and the remaining $0.3438 will be subsequently paid in 2014.
	The holders of the Series D preferred shares, as well as our previously issued preferred shares, have no voting rights other than the right to elect a specified number of directors if preferred share dividends are not declared and paid for a specified period.
	c)	Out of Period Adjustment
	Common share dividends were historically recognized as a reduction of retained earnings when paid. During 2012, we recognized a $31 million adjustment in our Consolidated Statement of Shareholders' Equity in order to reflect dividends within retained earnings when declared, with a corresponding increase in other liabilities in our Consolidated Balance Sheet. This adjustment did not impact net income or net income available to common shareholders.
	We believe that this matter was quantitatively and qualitatively immaterial to our previously issued financial statements and that the recognition of the adjustment in 2012 was similarly immaterial.

NONCONTROLLING_INTEREST

NONCONTROLLING INTEREST	12 Months Ended
	Dec. 31, 2013
Noncontrolling Interest [Abstract]	'
Noncontrolling Interest Disclosure [Text Block]	'
	During November 2013, the Company formed AXIS Ventures Reinsurance Limited (Ventures Re), a Bermuda domiciled insurer. Ventures Re was formed to write reinsurance on a fully collateralized basis.
	In conjunction with the formation of Ventures Re, third party investors purchased $50 million of non-voting redeemable preferred share capital issued by this entity. The preferred shares are redeemable at the sole discretion of Ventures Re's Board of Directors, and are expected to be redeemed on or before July 1, 2016.
	Ventures Re is considered to be a variable interest entity. The Company has concluded that it is the primary beneficiary of Ventures Re as it has the power to direct, and has more than an insignificant economic interest in, the activities of this entity. Following this determination, Ventures Re was consolidated by the Company. Shareholders' equity attributable to Ventures Re's third party investors is recorded in the Consolidated Financial Statements as noncontrolling interests.
	At December 31, 2013, total assets of Ventures Re were $50 million, consisting of cash and cash equivalents. The assets of Ventures Re can only be used to settle its own liabilities, and there is no recourse to the Company for any liabilities incurred by this entity.

RETIREMENT_PLANS

RETIREMENT PLANS	12 Months Ended
	Dec. 31, 2013
Compensation and Retirement Disclosure [Abstract]	'
RETIREMENT PLANS [Text Block]	'
	We provide defined contribution plans that are self directed to eligible employees through various plans sponsored by us. Generally, mutual funds are made available pursuant to which employees and we contribute a percentage of the employee’s gross salary into the plan each month.
	For eligible U.S. employees, we provide a non-qualified deferred compensation plan that enables them to make salary contributions in excess of those permitted under the AXIS 401(k) Plan, to make additional employee contributions from their bonus payments, and to receive discretionary employer contributions.
	We also provided supplemental executive retirement plans (“SERP”) to both the Chairman and the former CEO. We settled all obligations under our SERP during the third quarter of 2012, resulting in the recognition of an insignificant loss.
	During 2013, our total pension expenses were $20 million (2012: $20 million and 2011: $20 million) for the above retirement benefits.

SHAREBASED_COMPENSATION

SHARE-BASED COMPENSATION	12 Months Ended
	Dec. 31, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
SHARE-BASED COMPENSATION [Text Block]	'
	In May 2007, our shareholders approved the establishment of the AXIS Capital Holdings Limited 2007 Long-Term Equity Compensation Plan (“2007 Plan”). The 2007 Plan provides for, among other things, the grant of restricted stock, restricted stock units, non-qualified and incentive stock options, and other equity-based awards to our employees and directors. The 2007 Plan authorized the issuance of a total of 5,000,000 shares. In May of 2009 and 2012, our shareholders approved amendments to the 2007 Plan to increase the number of common shares authorized for issuance by 4,000,000 and 6,000,000 respectively, to bring the total number of common shares authorized for issuance to 15,000,000. As a result of the adoption of the 2007 Plan, the 2003 Long-Term Equity Compensation and 2003 Directors Long-Term Equity Compensation Plan were terminated, except that all related outstanding awards will remain in effect.
	We currently issue restricted stock and restricted stock units to our employees with service conditions, vesting generally over a period of 4 years with 25% of the award vesting annually. We also grant performance-based stock awards to certain employees in order to promote long-term growth and profitability. Performance-based awards represent the right to receive a specified number of common shares in the future, based upon the achievement of established performance criteria during the applicable performance period. At December 31, 2013, we anticipate that the established performance based criterion for these awards are likely to be achieved.
	Grants provided under the 2007 Plan generally allow for accelerated vesting provisions upon the employee’s death, permanent disability, or certain terminations following a change in control of the Company occurring within two years of the change in control event. Notwithstanding these vesting provisions, the Compensation Committee of our Board has broad authority to accelerate vesting at its own discretion.
	At December 31, 2013, 6,310,845 equity-based awards remained available for grant under the 2007 Plan. Between January 1, 2014 and February 10, 2014, a total of 1,890,523 restricted stock units and 91,917 performance-based restricted stock units were approved by the board of directors to be granted on March 1, 2014. Included in the total restricted stock awards granted subsequent to December 31, 2013 were 954,329 awards which will be settled in cash upon vesting.
	We have granted stock options under the 2003 Plans; however, none have been issued since 2005. All outstanding stock options are fully vested and exercisable. These options expire ten years from the date of grant.
	a)	Restricted Stock
	The following table provides a reconciliation of the beginning and ending balance of nonvested restricted stock (including restricted stock units) for the year ended December 31, 2013:
			Performance-based Stock Awards				Service-based Stock Awards
			Number of		Weighted Average		Number of			Weighted Average
			Restricted		Grant Date		Restricted			Grant Date
			Stock		Fair Value		Stock			Fair Value
		Nonvested restricted stock - beginning of year	250		$	34.42	4,429			$	32.48
		Granted	33		45.89		975			39.31
		Vested	—		—		(1,754	)		32.03
		Forfeited	—		—		(220	)		34.17
		Nonvested restricted stock - end of year	283		$	35.74	3,430			$	34.72
	(1) Fair value is based on the closing price of our common shares on the New York Stock Exchange on the day of the grant.
	During 2013, we granted 1,007,425 restricted stock awards (2012: 2,447,700; 2011: 1,839,250) to our employees with a weighted average grant-date fair value per share of $39.52 (2012: $32.20; 2011: $36.12).
	During 2013, we incurred a compensation cost of $57 million (2012: $68 million; 2011: $39 million) in respect of all restricted stock and restricted stock units, and recorded tax benefits thereon of $10 million (2012: $8 million; 2011: $7 million). Compensation costs incurred in 2012 includes $20 million of accelerated and incremental expenses associated with the transition in our senior leadership. The retirement of one senior leader resulted in the modification of that leader's outstanding restricted stock awards to eliminate the previously existing service condition. The unanticipated termination without cause of another senior officer lead to the early satisfaction of employment obligations and resulted in the service condition associated with that officer's outstanding restricted stock awards being fully satisfied.
	b)	Cash-settled Awards
	During 2013, we also granted 847,425 restricted stock units that will settle in cash rather than shares when the awards ultimately vest. At December 31, 2013, the corresponding liability for cash-settled awards, included in other liabilities on the Consolidated Balance Sheets, was $9 million (2012: $nil).
	The total fair value of restricted stock and cash settled awards vested during 2013 was $56 million (2012: $43 million; 2011: $63 million). At December 31, 2013, we had unrecognized compensation costs of $98 million (2012: $89 million) which are expected to be recognized over the weighted average period of 2.4 years (2012: 2.5 years).
	c)	Stock options
	The following is a summary of stock options outstanding and exercisable at December 31, 2013 and related activity for the year ended:
			Number		Weighted		Weighted		Aggregate
			of Stock		Average		Average		Intrinsic
			Options		Exercise		Remaining		Value(1)
					Price		Contractual
							Term
		Outstanding and exercisable - beginning of year	919		$	28.74
		Granted	—		—
		Exercised	(706	)	28.96
		Expired	—		—
		Outstanding and exercisable - end of year	213		$	27.98	1		$	4,180
	-1	The aggregate intrinsic value in the table above represents the total pre-tax intrinsic value (the difference between our closing stock price at December 31, 2013 and the exercisable price, multiplied by the number of in-the-money-options) that would have been received by the stock option holder had all stock option holders exercised their stock options on December 31, 2013.
	The total intrinsic value of stock options exercised during 2013 was $10 million (2012: $11 million) and we received proceeds of $17 million (2012: $3 million). For these exercised stock options, we issued new shares from the authorized share capital pool rather than from our treasury pool.

RELATED_PARTY_TRANSACTIONS

RELATED PARTY TRANSACTIONS	12 Months Ended
	Dec. 31, 2013
Related Party Transactions [Abstract]	'
Related Party Transactions [Text Block]	'
	The transactions listed below are classified as related party transactions as each counterparty had or has had either a direct or indirect shareholding in us or has been a board member during any period covered by the financial statements.
	The collateral manager of four of our CLOs is Blackstone Debt Advisors L.P., who is entitled to management fees payable by the collateralized obligations in the ordinary course of business. We also have investments in two hedge funds managed by Blackstone Alternative Asset Management, LP, who is entitled to management fees in the ordinary course of business. On June 30, 2012, Blackstone Group ceased to be a related party. Fees due or paid for the six months ended June 30, 2012 were $1 million. In 2011, total fees paid were $2 million.
	In the ordinary course of business, we engage SKY Harbor Capital Management, LLC for asset management services for certain of our short duration high yield debt portfolios and StoneRiver RegEd for broker and adjuster licensing, appointment and compliance services. During 2013, total fees paid to these Stone Point Group companies were $2 million (2012: $2 million; 2011: nil).

INCOME_TAXES

INCOME TAXES	12 Months Ended
	Dec. 31, 2013
Income Tax Disclosure [Abstract]	'
INCOME TAXES [Text Block]	'
	Under current Bermuda law, our Bermuda domiciled companies are not required to pay any taxes in Bermuda on income or capital gains. We have received an assurance from the Minister of Finance in Bermuda that, in the event of any taxes being imposed, we will be exempt from taxation in Bermuda until March 2035. Our primary Bermuda subsidiary has an operating branch in Singapore, which is subject to the relevant taxes in that jurisdiction. The branch is not under examination in this tax jurisdiction, but remains subject to examination for tax years 2010 through 2013.
	Our U.S. subsidiaries are subject to federal, state and local corporate income taxes and other taxes applicable to U.S. corporations. The provision for federal income taxes has been determined under the principles of the consolidated tax provisions of the U.S. Internal Revenue Code and Regulations. Should the U.S. subsidiaries pay a dividend outside the U.S. group, withholding taxes will apply. Our U.S. subsidiaries are not under examination but remain subject to examination in the U.S. for tax years 2010 through 2013.
	In Canada, our U.S. reinsurance company operates through a branch and our U.S. service company has an unlimited liability company subsidiary based in Canada. These Canadian operations are subject to the relevant taxes in that jurisdiction and generally remain subject to examination for tax years 2009 through 2013. During the year, our Canadian reinsurance branch was audited by the Canada Revenue Agency for income taxes for tax years 2009 and 2010, with no material adjustments.
	We also have subsidiaries in Ireland, the United Kingdom (U.K.), Australia and Brazil. These subsidiaries and their branches, are not under examination, but generally remain subject to examination in all applicable jurisdictions for tax years 2009 through 2013.
	The following table provides an analysis of our income tax expense and net tax assets:
		Year ended December 31,	2013			2012			2011
		Current income tax expense (benefit)
		United States	$	12,466		$	4,931		$	5,064
		Europe	9,039			8,566			9,598
		Other	—			(174		)	188
		Deferred income tax expense (benefit)
		United States	(13,976		)	(10,749		)	1,379
		Europe	(526		)	713			(996		)
		Other	(1		)	—			—
		Total income tax expense	$	7,002		$	3,287		$	15,233
		Net current tax receivables	$	5,689		$	1,164		$	1,318
		Net deferred tax assets	80,258			52,794			60,836
		Net tax assets	$	85,947		$	53,958		$	62,154
	Deferred income taxes reflect the tax impact of temporary differences between the carrying amounts of assets and liabilities for financial reporting and income tax purposes. The significant components of our deferred tax assets and liabilities were as follows:
		At December 31,	2013			2012
		Deferred tax assets:
		Discounting of loss reserves	$	59,023		$	61,534
		Unearned premiums	39,146			32,355
		Operating loss carryforwards	20,316			20,685
		Accruals not currently deductible	39,018			25,638
		Other investment adjustments and impairments	7,859			8,790
		Tax credits	11,886			7,945
		Depreciation	2,410			3,858
		Other deferred tax assets	2,906			2,185
		Deferred tax assets before valuation allowance	182,564			162,990
		Valuation allowance	(25,542		)	(24,574		)
		Deferred tax assets net of valuation allowance	157,022			138,416
		Deferred tax liabilities:
		Deferred acquisition costs	(37,226		)	(27,211		)
		Net unrealized gains on investments	(23,200		)	(44,137		)
		Amortization of intangible assets and goodwill	(10,059		)	(8,258		)
		Accrued market discounts	(1,151		)	(1,323		)
		Equalization reserves	(2,080		)	(1,957		)
		Other deferred tax liabilities	(3,048		)	(2,736		)
		Deferred tax liabilities	(76,764		)	(85,622		)
		Net deferred tax assets	$	80,258		$	52,794
	At December 31, 2013, the total operating loss carryforwards for our Singapore and Australian branches were $115 million (2012: $117 million) and $45 million (2012: $51 million), respectively. Such operating losses are currently available to offset future taxable income of the branches and may be carried forward indefinitely in each jurisdiction. At December 31, 2013, our European subsidiaries have a $4 million (2012: $3 million) foreign tax credit which can be carried forward indefinitely. In addition, at December 31, 2013, our U.S. companies have a $7 million (2012: $5 million) alternative minimum tax credit that can be carried forward indefinitely.
	The following table provides an analysis of the movement in our valuation allowance:
		At December 31,	2013			2012
		Income tax expense:
		Valuation allowance - beginning of year	$	33,933		$	30,623
		Operating loss carryforwards	(794		)	635
		Foreign tax credit	1,762			2,675
		Change in investment-related items	(7,831		)	—
		Valuation allowance - end of year	27,070			33,933
		Accumulated other comprehensive income:
		Valuation allowance - beginning of year	(9,359		)	(9,359		)
		Change in investment-related items	7,831			—
		Valuation allowance - end of year	(1,528		)	(9,359		)
		Total valuation allowance - end of year	$	25,542		$	24,574
	At December 31, 2013 and 2012, we established a full valuation allowance on: (1) operating loss carryforwards relating to branch operations in Australia and Singapore due to cumulative losses in recent years; (2) unutilized foreign tax credits available in Ireland and (3) certain other deferred tax assets related to branch operations.
	Although realization is not assured, management believes it is more likely than not that the tax benefit of the recorded net deferred tax assets will be realized. Other than the items discussed above, the remaining gross deferred tax assets relate substantially to our U.S. operations. In evaluating our ability to recover these tax assets within the jurisdiction from which they arise, we consider all available positive and negative evidence, including historical results, operating loss carryback potential and scheduled reversals of deferred tax liabilities. Our U.S. operations have produced significant taxable income in prior periods and have deferred tax liabilities that will reverse in future periods such that we believe sufficient ordinary taxable income is available to utilize all remaining ordinary deferred tax assets. In 2013 and 2012, there were sufficient net unrealized gains to offset remaining impairments, therefore a valuation allowance on such impairments in the U.S., was not considered necessary.
	There were no unrecognized tax benefits at December 31, 2013 and 2012.
	The following table presents the distribution of income before income taxes between domestic and foreign jurisdictions as well as a reconciliation of the actual income tax rate to the amount computed by applying the effective tax rate of 0% under Bermuda law to income before income taxes:
		Year ended December 31,	2013			2012			2011
		Income before income taxes
		Bermuda (domestic)	$	625,490		$	485,613		$	10,911
		Foreign	108,977			64,915			50,627
	Total income before income taxes	$	734,467		$	550,528		$	61,538
	Reconciliation of effective tax rate (% of income before income taxes)
	Expected tax rate	0		%	0		%	0		%
	Foreign taxes at local expected rates:
	United States	2.1		%	0.4		%	33.2		%
	Europe	1		%	1.4		%	10.7		%
	Other	0.3		%	—		%	3.3		%
	Valuation allowance	(0.7		)%	0.6		%	(15.5		)%
	Net tax exempt income	(1.3		)%	(1.5		)%	(11.2		)%
	Other	(0.4		)%	(0.3		)%	4.3		%
	Actual tax rate	1		%	0.6		%	24.8		%

OTHER_COMPREHENSIVE_INCOME_LOS

OTHER COMPREHENSIVE INCOME (LOSS)	12 Months Ended
	Dec. 31, 2013
Equity [Abstract]	'
OTHER COMPREHENSIVE INCOME (LOSS) [Text Block]	'
	The tax effects allocated to each component of other comprehensive income (loss) were as follows:
			Before Tax Amount				Tax (Expense) Benefit				Net of Tax Amount
		Year ended December 31, 2013
		Available for sale investments:
		Unrealized investment losses arising during the period	$	(169,614	)		$	7,782			$	(161,832	)
		Adjustment for reclassification of net realized investment gains and OTTI losses recognized in net income	(67,156		)		5,605				(61,551		)
		Unrealized investment losses arising during the period, net of reclassification adjustment	(236,770		)		13,387				(223,383		)
		Non-credit portion of OTTI losses	—				—				—
		Foreign currency translation adjustment	(21,414		)		—				(21,414		)
		Net change in benefit plan assets and obligations recognized in equity and reclassification adjustment	—				—				—
		Total other comprehensive loss	$	(258,184	)		$	13,387			$	(244,797	)
		Year ended December 31, 2012
		Available for sale investments:
		Unrealized investment gains arising during the period	$	378,040			$	(29,530	)		$	348,510
		Adjustment for reclassification of net realized investment gains and OTTI losses recognized in net income	(127,828		)		11,550				(116,278		)
		Unrealized investment gains arising during the period, net of reclassification adjustment	250,212				(17,980		)		232,232
		Non-credit portion of OTTI losses	—				—				—
		Foreign currency translation adjustment	510				—				510
		Net change in benefit plan assets and obligations recognized in equity and reclassification adjustment	1,718				—				1,718
		Total other comprehensive income	$	252,440			$	(17,980	)		$	234,460
		Year ended December 31, 2011
		Available for sale investments:
		Unrealized investment gains arising during the period	87,384				(13,087		)		74,297
		Adjustment for reclassification of net realized investment gains and OTTI losses recognized in net income	(121,248		)		1,700				(119,548		)
		Unrealized investment losses arising during the period, net of reclassification adjustment	(33,864		)		(11,387		)		(45,251		)
		Non-credit portion of OTTI losses	(585		)		130				(455		)
		Foreign currency translation adjustment	(3,045		)		—				(3,045		)
		Net change in benefit plan assets and obligations recognized in equity and reclassification adjustment	92				—				92
		Total other comprehensive loss	(37,402		)		(11,257		)		(48,659		)
	Reclassifications out of AOCI into net income available to common shareholders were as follows:
				Amount Reclassified from AOCI(1)
		Details About AOCI Components	Consolidated Statement of Operations Line Item That Includes Reclassification	Year ended December 31,
				2013				2012				2011
		Unrealized appreciation on available for sale investments
			Other realized investment gains	$	76,518			$	152,062			$	137,694
			OTTI losses	(9,362		)		(24,234		)		(16,446		)
			Total before tax	67,156				127,828				121,248
			Tax expense	(5,605		)		(11,550		)		(1,700		)
			Net of tax	$	61,551			$	116,278			$	119,548
		Supplemental Executive Retirement Plans (SERPs)
		Net change in benefit plan assets and obligations	General and administrative expenses	$	—			$	(1,718	)		$	(92	)
			Tax benefit	—				—				—
			Net of tax	$	—			$	(1,718	)		$	(92	)
	-1	Amounts in parentheses are debits to net income available to common shareholders

STATUTORY_FINANCIAL_INFORMATIO

STATUTORY FINANCIAL INFORMATION	12 Months Ended
	Dec. 31, 2013
Statutory Accounting Practices, Statutory Amount Available for Dividend Payments [Abstract]	'
STATUTORY FINANCIAL INFORMATION [Text Block]	'
	Our (re)insurance operations are subject to insurance and/or reinsurance laws and regulations in the jurisdictions in which they operate, the most significant of which include Bermuda, Ireland and the United States. These regulations include certain restrictions on the amount of dividends or other distributions, such as loans or cash advances, available to shareholders without prior approval of the insurance regulatory authorities.
	The statutory capital and surplus in each of our most significant regulatory jurisdictions at December 31, 2013 and 2012 was as follows:
			Bermuda				Ireland				United States
		At December 31,	2013		2012		2013		2012		2013		2012
		Required statutory capital and surplus	$	1,996,794	$	2,048,329	$	315,258	$	279,078	$	385,651	$	358,674
		Actual statutory capital and surplus	$	3,839,840	$	4,091,437	$	906,932	$	904,237	$	1,348,861	$	1,295,679
	Under the Insurance Act 1978, amendments thereto and Related Regulations of Bermuda (the "Act"), our Bermuda subsidiary, AXIS Specialty Bermuda is required to maintain minimum statutory capital and surplus equal to the greater of a minimum solvency margin ("MSM") and the Enhanced Capital Requirement ("ECR"). The MSM is the greater of $100 million, 50% of net written premiums or 15% of the net reserve for losses and loss adjustment expenses and the ECR is calculated based on either an internally developed risk-based capital model or a standard risk-based capital model developed by the Bermuda Monetary Authority. Under the Act, AXIS Specialty Bermuda is restricted as to the payment of dividends and/or distributions for amounts greater than 25% of the prior year’s statutory capital and surplus, whereby a signed affidavit by at least two members of the Board of Directors attesting that a dividend and/or distribution in excess of this amount would not cause the company to fail to meet its relevant margins is required. At December 31, 2013, the maximum dividend/distribution AXIS Specialty Bermuda could pay, without a signed affidavit, having met minimum levels of statutory capital and surplus requirements, was approximately $1 billion.
	Our Irish subsidiaries, AXIS Specialty Europe SE and AXIS Re SE, are required to maintain minimum levels of statutory and capital surplus. At December 31, our subsidiaries were in compliance with these requirements. Our Irish subsidiaries may declare dividends out of retained earnings subject to meeting their solvency and capital requirements, which are to hold statutory capital and surplus equal to or exceeding the Required Solvency Margin (RSM). The RSM is calculated with reference to Solvency I regulations. The maximum dividend is limited to "profits available for distribution", which consists of accumulated realized profits less accumulated realized losses. At December 31, 2013, the maximum dividend our Irish subsidiaries could pay out of retained earnings, after obtaining prior approval from the Irish regulator, was approximately $141 million.
	Our U.S. operations required statutory capital and surplus is determined using risk based capital tests, which is the threshold that constitutes the authorized control level. If a company falls below the control level, the commissioner is authorized to take whatever regulatory actions may be considered necessary to protect policyholders and creditors. The maximum dividend that may be paid by our U.S. insurance subsidiaries is restricted by the regulatory requirements of the domiciliary states. Generally, the maximum dividend that may be paid by each of our U.S. insurance subsidiaries is limited to unassigned surplus (statutory equivalent of retained earnings) and may also be limited to statutory net income, net investment income or 10% of total statutory capital and surplus. At December 31, 2013, the maximum dividend that our U.S. insurance operations could pay without regulatory approval was approximately $135 million.
	Our operating subsidiaries in Bermuda and the United States maintain branch offices in Singapore and Canada, respectively. Our Irish operating subsidiaries maintain branch offices in Switzerland, Australia and the United Kingdom. As branch offices are not considered separate entities for regulatory purposes, the required and actual statutory capital and surplus amounts for each jurisdiction in the table above include amounts related to the applicable branch offices. Our Singaporean, Australian and Canadian branch offices are subject to additional minimum capital or asset requirements in their countries of domicile. At December 31, 2013 and 2012, the actual capital/assets for each of these branches exceeded the relevant local regulatory requirements.
	Total statutory net income of our operating subsidiaries was $766 million, $697 million, $99 million for 2013, 2012 and 2011, respectively. The differences between statutory financial statements and statements prepared in accordance with U.S. GAAP vary by jurisdiction; however, the primary differences are that statutory financial statements do not reflect deferred acquisition costs, certain net deferred tax assets, goodwill and intangible assets, unrealized appreciation on debt securities or certain unauthorized reinsurance recoverables.

UNAUDITED_CONDENSED_QUARTERLY_

UNAUDITED CONDENSED QUARTERLY FINANCIAL DATA	12 Months Ended
	Dec. 31, 2013
Quarterly Financial Information Disclosure [Abstract]	'
UNAUDITED CONDENSED QUARTERLY FINANCIAL DATA [Text Block]	'
	The following is an unaudited summary of our quarterly financial results:
		Quarters ended	31-Mar		30-Jun		30-Sep			31-Dec
		2013
		Net premiums earned	$	874,039	$	945,873	$	945,242		$	941,911
		Net investment income	108,908		83,112		103,429			113,863
		Net realized investment gains (losses)	44,478		16,235		(4,708		)	19,558
		Underwriting income	170,799		9,921		153,088			94,159
		Net income available to common shareholders	302,816		72,447		137,121			171,524
		Earnings per common share - basic	$	2.59	$	0.63	$	1.23		$	1.55
		Earnings per common share - diluted	$	2.55	$	0.62	$	1.21		$	1.52
		2012
		Net premiums earned	$	846,362	$	850,603	$	862,447		$	856,049
		Net investment income	116,023		74,449		103,638			86,847
		Net realized investment gains	14,491		30,405		50,803			31,771
		Underwriting income (loss)	62,689		119,739		154,999			(74,291		)
		Net income (loss) available to common shareholders	121,997		168,152		223,407			(18,551		)
		Earnings (loss) per common share - basic	$	0.97	$	1.36	$	1.84		$	(0.16	)
		Earnings (loss) per common share - diluted	$	0.96	$	1.35	$	1.82		$	(0.16	)

SCHEDULE_II_CONDENSED_FINANCIA

SCHEDULE II - CONDENSED FINANCIAL INFORMATION OF PARENT COMPANY	12 Months Ended
	Dec. 31, 2013
Condensed Financial Information of Parent Company Only Disclosure [Abstract]	'
Schedule II - Condensed Financial Information of Parent Company [Text Block]	'
	AXIS CAPITAL HOLDINGS LIMITED
	CONDENSED BALANCE SHEETS – PARENT COMPANY
	DECEMBER 31, 2013 AND 2012
		2013			2012
		(in thousands)
	Assets
	Investments in subsidiaries on equity basis	$	6,581,368		$	6,571,607
	Cash and cash equivalents	4,414			2,841
	Other assets	3,179			2,706
	Total assets	$	6,588,961		$	6,577,154
	Liabilities
	Intercompany payable	$	204,877		$	243,252
	Senior notes	499,906			499,798
	Dividends payable	47,959			37,370
	Other liabilities	18,257			16,973
	Total liabilities	770,999			797,393
	Shareholders’ equity
	Preferred shares	627,843			502,843
	Common shares (2013: 174,134; 2012: 171,867 shares issued	2,174			2,146
	and 2013: 109,485; 2012: 117,920 shares outstanding)
	Additional paid-in capital	2,240,125			2,179,034
	Accumulated other comprehensive income	117,825			362,622
	Retained earnings	5,062,706			4,497,789
	Treasury shares, at cost (2013: 64,649; 2012: 53,947 shares)	(2,232,711		)	(1,764,673		)
	Total shareholders’ equity	5,817,962			5,779,761
	Total liabilities and shareholders’ equity	$	6,588,961		$	6,577,154
	-1	On November 15, 2004, AXIS Capital issued $500 million aggregate principal amount of 5.75% senior unsecured debt (“Senior Notes”) at an issue price of 99.785%, generating net proceeds of $496 million. Interest of the 5.75% Senior Notes is payable semi-annually in arrears on June 1 and December 1 of each year, beginning on June 1, 2005. Unless previously redeemed, the 5.75% Senior Notes will mature on December 1, 2014.
	-2	AXIS Capital has fully and unconditionally guaranteed all obligations of AXIS Specialty Finance, a 100% owned finance subsidiary, related to the issuance of $500 million aggregate principal amount of 5.875% senior unsecured notes. AXIS Capital’s obligations under this guarantee are unsecured and senior and rank equally with all other senior obligations of AXIS Capital.
	-3	AXIS Capital has fully and unconditionally guaranteed the derivative instrument obligations of certain of its 100% owned operating subsidiaries. At December 31, 2013, the fair value of guaranteed obligations utilized aggregated to $28 million (2012: $nil).
	SCHEDULE II
	AXIS CAPITAL HOLDINGS LIMITED
	CONDENSED STATEMENTS OF OPERATIONS – PARENT COMPANY
	YEARS ENDED DECEMBER 31, 2013, 2012 AND 2011
		2013			2012			2011
		(in thousands)
	Revenues
	Net investment income	$	5		$	25		$	1
	Total revenues	5			25			1
	Expenses
	General and administrative expenses	40,565			62,293			36,248
	Interest expense and financing costs	29,201			29,201			29,201
	Total expenses	69,766			91,494			65,449
	Loss before equity in net earnings of subsidiaries	(69,761		)	(91,469		)	(65,448		)
	Equity in net earnings of subsidiaries	797,226			638,710			111,753
	Net income	727,465			547,241			46,305
	Preferred share dividends	40,474			38,228			36,875
	Loss on repurchase of preferred shares	3,081			14,009			—
	Net income available to common shareholders	$	683,910		$	495,004		$	9,430
	Comprehensive income (loss)	$	482,668		$	781,701		$	(2,354	)
	SCHEDULE II
	AXIS CAPITAL HOLDINGS LIMITED
	CONDENSED STATEMENTS OF CASH FLOWS – PARENT COMPANY
	YEARS ENDED DECEMBER 31, 2013, 2012 AND 2011
		2013			2012			2011
		(in thousands)
	Cash flows from operating activities:
	Net income	$	727,465		$	547,241		$	46,305
	Adjustments to reconcile net income to net cash provided by operating activities:
	Equity in net earnings of subsidiaries	(797,226		)	(638,710		)	(111,753		)
	Change in intercompany payable	(38,375		)	(7,667		)	(44,503		)
	Dividends received from subsidiaries	566,000			525,000			255,000
	Other items	34,803			56,425			21,298
	Net cash provided by operating activities	492,667			482,289			166,347
Cash flows from investing activities:
Capital repaid from subsidiary	—			—			130,000
Net cash from investing activities	—			—			130,000
Cash flows from financing activities:
Net proceeds from issuance of preferred shares	218,449			393,544			—
Repurchase of preferred shares	(100,000		)	(404,073		)	—
Repurchase of common shares	(472,263		)	(317,687		)	(65,885		)
Dividends paid - common shares	(118,426		)	(120,487		)	(206,455		)
Dividends paid - preferred shares	(39,193		)	(38,228		)	(36,875		)
Proceeds from issuance of common shares	20,339			5,120			6,735
Net cash used in financing activities	(491,094		)	(481,811		)	(302,480		)
Increase (decrease) in cash and cash equivalents	1,573			478			(6,133		)
Cash and cash equivalents - beginning of period	2,841			2,363			8,496
Cash and cash equivalents - end of period	$	4,414		$	2,841		$	2,363
Supplemental disclosures of cash flow information:
Interest paid	$	28,750		$	28,750		$	28,750

SCHEDULE_III_SUPPLEMENTARY_INS

SCHEDULE III - SUPPLEMENTARY INSURANCE INFORMATION	12 Months Ended
	Dec. 31, 2013
Supplementary Insurance Information [Abstract]	'
SUPPLEMENTARY INSURANCE INFORMATION [Text Block]	'
	AXIS CAPITAL HOLDINGS LIMITED
	SUPPLEMENTARY INSURANCE INFORMATION
			At and year ended December 31, 2013
	(in thousands)		Deferred		Reserve		Unearned		Net		Net		Losses		Amortization		Other		Net
			Acquisition		for Losses		Premiums		Premiums		Investment		And Loss		of Deferred		Operating		Premiums
			Costs		and Loss				Earned		Income(1)		Expenses		Acquisition		Expenses(2)		Written
					Expenses										Costs
	Insurance		$	150,109	$	4,873,184	$	1,548,653	$	1,722,762	$	—	$	1,050,402	$	242,363	$	347,684	$	1,813,538
	Reinsurance		306,013		4,708,956		1,135,196		1,984,303		—		1,083,793		421,828		137,450		2,114,662
	Corporate		—		—		—		—		409,312		—		—		90,256		—
	Total		$	456,122	$	9,582,140	$	2,683,849	$	3,707,065	$	409,312	$	2,134,195	$	664,191	$	575,390	$	3,928,200
			At and year ended December 31, 2012
	(in thousands)		Deferred		Reserve		Unearned		Net		Net		Losses		Amortization		Other		Net
			Acquisition		for Losses		Premiums		Premiums		Investment		And Loss		of Deferred		Operating		Premiums
			Costs		and Loss				Earned		Income(1)		Expenses		Acquisition		Expenses(2)		Written
					Expenses										Costs
	Insurance		$	128,311	$	4,492,553	$	1,456,318	$	1,558,058	$	—	$	953,564	$	226,859	$	314,834	$	1,522,245
	Reinsurance		260,937		4,566,178		998,374		1,857,405		—		1,142,464		400,794		116,487		1,815,211
	Corporate		—		—		—		—		380,957		—		—		129,660		—
	Total		$	389,248	$	9,058,731	$	2,454,692	$	3,415,463	$	380,957	$	2,096,028	$	627,653	$	560,981	$	3,337,456
			At and year ended December 31, 2011
	(in thousands)		Deferred		Reserve		Unearned		Net		Net		Losses		Amortization		Other		Net
			Acquisition		for Losses		Premiums		Premiums		Investment		And Loss		of Deferred		Operating		Premiums
			Costs		and Loss				Earned		Income(1)		Expenses		Acquisition		Expenses(2)		Written
					Expenses										Costs
	Insurance		$	142,743	$	4,081,741	$	1,412,699	$	1,429,687	$	—	$	919,319	$	199,583	$	278,147	$	1,466,134
	Reinsurance		264,784		4,343,304		1,041,763		1,885,274		—		1,755,733		387,886		103,915		1,953,300
	Corporate		—		—		—		—		362,430		—		—		77,089		—
	Total		$	407,527	$	8,425,045	$	2,454,462	$	3,314,961	$	362,430	$	2,675,052	$	587,469	$	459,151	$	3,419,434
	-1	As we evaluate the underwriting results of each of our reportable segments separately from the results of our investment portfolio, we do not allocate net investment income to our reportable segments.
	-2	Amounts related to our reportable segments reflect underwriting-related general and administrative expenses, including those incurred directly by segment personnel and certain corporate overhead costs allocated based on estimated consumption, headcount and other variables deemed relevant. Other corporate overhead costs, which are are not incremental and/or directly attributable to our individual underwriting operations, are not allocated to our reportable segments and are presented separately as corporate expenses.

SCHEDULE_IV_SUPPLEMENTARY_REIN

SCHEDULE IV - SUPPLEMENTARY REINSURANCE INFORMATION	12 Months Ended
	Dec. 31, 2013
Supplemental Schedule of Reinsurance Premiums for Insurance Companies [Abstract]	'
SUPPLEMENTARY REINSURANCE INFORMATION [Text Block]	'
	AXIS CAPITAL HOLDINGS LIMITED
	SUPPLEMENTARY REINSURANCE INFORMATION
	YEARS ENDED DECEMBER 31, 2013, 2012 AND 2011
		(in thousands)	DIRECT		CEDED TO		ASSUMED		NET		PERCENTAGE
			GROSS		OTHER		FROM		AMOUNT		OF AMOUNT
			PREMIUM		COMPANIES		OTHER				ASSUMED TO
							COMPANIES				NET
		2013	$	1,974,915	$	768,841	$	2,722,126	$	3,928,200	69.3	%
		2012	1,805,887		802,187		2,333,756		3,337,456		69.9	%
		2011	1,696,600		676,719		2,399,553		3,419,434		70.2	%

SIGNIFICANT_ACCOUNTING_POLICIE1

SIGNIFICANT ACCOUNTING POLICIES (POLICIES)	12 Months Ended
	Dec. 31, 2013
Policy Text Block [Abstract]	'
Basis of presentation [Policy Text Block]	'
	These consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States (“U.S. GAAP”) and include the accounts of AXIS Capital, its wholly-owned subsidiaries, and variable interest entities (“VIEs”) in which the Company is considered the primary beneficiary.
	Tabular dollar and share amounts are in thousands, with the exception of per share amounts. All amounts are reported in U.S. dollars. To facilitate comparison of information across periods, certain reclassifications have been made to prior year amounts to conform to the current year's presentation.
Consolidation/VIEs [Policy Text Block]	'
	All inter-company accounts and transactions have been eliminated.
	A VIE is an entity that either: (a) does not have equity investors with voting rights or (b) has equity investors that do not provide sufficient financial resources for the entity to support its activities. We are the primary beneficiary of a VIE if we have a controlling financial interest in the VIE, based on the following two characteristics: a) the power to direct the activities of the VIE that most significantly impact the economic performance of the VIE, and b) the obligation to absorb losses of the VIE that could potentially be significant to the VIE or the right to receive benefits from the VIE that could potentially be significant to the VIE.
Use of estimates [Policy Text Block]	'
	The preparation of these consolidated financial statements requires management to make estimates and assumptions that affect the reported amount of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. While management believes that the amounts included in the consolidated financial statements reflect its best estimates and assumptions, actual results could differ from those estimates. The Company’s principal estimates include:
	•	reserve for losses and loss expenses;
	•	reinsurance recoverable on unpaid losses, including the provision for uncollectible amounts;
	•	gross and net premiums written and net premiums earned;
	•	other-than-temporary impairments (“OTTI”) in the carrying value of available-for-sale investment securities; and
	•	fair value measurements for our financial assets and liabilities.
Investments [Policy Text Block]	'
	Investments available for sale
	Our fixed maturities and equities classified as “available for sale” are reported at fair value at the balance sheet date. See Note 6 – Fair Value Measurements for additional information regarding the determination of fair value. The change in fair value (net unrealized gain or loss) on our available for sale investments, net of tax, is included as a separate component of accumulated other comprehensive income (loss) (“AOCI”) in shareholders’ equity.
	Net investment income includes interest and dividend income and the amortization of market premiums and discounts and is presented net of investment expenses. Investment income is recognized when earned. Purchases and sales of investments are recorded on a trade-date basis and realized gains/losses on sales of investments are determined based on the specific identification method.
	We recognize investment income from fixed maturities based on the constant effective yield method, which includes an adjustment for estimated principal repayments, if any. The effective yield used to determine the amortization for fixed maturities subject to prepayment risk (e.g. asset-backed, loan-backed and other structured securities) is recalculated and adjusted periodically based upon actual historical and/or projected future cash flows. The adjustments to the yield for highly-rated prepayable fixed maturities are accounted for using the retrospective method. The adjustments to the yield for other prepayable fixed maturities are accounted for using the prospective method.
	On a quarterly basis, we assess whether unrealized losses on available for sale investments represent impairments that are other than temporary. Several factors are considered in this assessment including, but not limited to: (i) the extent and duration of the decline, (ii) the reason for the decline (e.g. credit spread widening, credit event, foreign exchange rate movements), (iii) the historical and implied future volatility of the fair value, (iv) the financial condition and near-term prospects of the issuer and (v) the collateral structure and credit support of the security, if applicable.
	A fixed maturity is impaired when the fair value is below its amortized cost. For an impaired fixed maturity where we intend to sell the security or it is more likely than not that we will be required to sell the security before its anticipated recovery, the full amount of the impairment is charged to earnings and is included in net realized investment gains (losses). Where we intend to hold the impaired fixed maturity, we estimate the anticipated credit loss of the security and recognize only this portion of the impairment in earnings, with the remaining non-credit related balance of the impairment (i.e. related to interest rates, market conditions, etc.) recognized in AOCI.
	We impair an equity security in an unrealized loss position when we do not have the ability and intent to hold the security for a reasonable period of time to allow for a full recovery. The full impairment is charged to earnings and is included in net realized investment gains (losses).
	Upon recognition of an OTTI, the new cost basis for the security is the previous amortized cost for a fixed maturity or cost for an equity security less the OTTI recognized in earnings. The new cost basis is not adjusted for subsequent recoveries in fair value; except for fixed maturities whereby the difference between the new cost basis and the expected cash flows is accreted on a quarterly basis to net investment income over the remaining life of the fixed maturity.
	Other investments
	We record other investments at fair value (see Note 6 – Fair Value Measurements), with both changes in fair value and realized gains/losses reported in net investment income.
	Short-term investments
	Short-term investments primarily comprise highly-liquid debt securities with maturities greater than three months but less than one year from the date of purchase. These investments are carried at amortized cost, which approximates fair value.
Cash and cash equivalents [Policy Text Block]	'
	Cash equivalents include money-market funds and fixed interest deposits placed with a maturity of under 90 days when purchased. Cash and cash equivalents are recorded at amortized cost, which approximates fair value due to the short-term, liquid nature of these securities. Our restricted cash balance primarily relates to funds held in trust in support of our obligations in regulatory jurisdictions where we operate as a non-admitted carrier.
Premiums (gross premiums written) [Policy Text Block]	'
	Insurance premiums written are recorded in accordance with the terms of the underlying policies. Reinsurance premiums are recorded at the inception of the contract and are estimated based upon information received from ceding companies. For multi-year contracts where (re)insurance premiums are payable in annual installments, premiums are recorded at the inception of the contract based on management’s best estimate of total premiums to be received. However, premiums are normally recognized on an annual basis for multi-year contracts where the cedant has the ability to unilaterally commute or cancel coverage within the term of the policy. The remaining annual premiums are included as written at each successive anniversary date within the multi-year term.
	Any subsequent differences arising on insurance and reinsurance premium estimates are recorded in the period they are determined.
Premiums (net premiums earned) [Policy Text Block]	'
	(Re)insurance premiums are earned evenly over the period during which we are exposed to the underlying risk, which is generally one to two years with the exception of multi-year contracts. Unearned premiums represent the portion of premiums written which is applicable to the unexpired risks under contracts in force.
	Reinstatement premiums are recognized and earned at the time a loss event occurs, where the coverage limits for the remaining life of the contract are reinstated under pre-defined contract terms. The accrual of reinstatement premiums is based on our estimate of losses and loss adjustment expenses, which reflects management’s judgment, as described in Note 2(d) – Losses and Loss Expenses below.
Premiums (receivables) [Policy Text Block]	'
	Premiums receivable balances are reviewed for impairment at least quarterly and an allowance is established for amounts considered uncollectible. The need for charge-off of any amounts previously reserved as uncollectible is assessed on a quarterly basis.
Acquisition costs [Policy Text Block]	'
	Acquisition costs vary with and are directly related to the acquisition of (re)insurance contracts and consist primarily of fees and commissions paid to brokers and premium taxes. Premiums receivable are presented net of applicable acquisition costs when contract terms provide for the right of offset. Acquisition costs are shown net of commissions earned on ceded reinsurance. Our net acquisition costs are deferred and charged to expense as the related premium is earned.
	Anticipated losses and loss expenses, other costs and investment income related to these premiums are considered in assessing the recoverability of our deferred acquisition costs. If deferred amounts are estimated to be unrecoverable, they are expensed. Compensation expenses for personnel involved in contract acquisition, as well as advertising costs, are expensed as incurred.
Losses and loss expenses [Policy Text Block]	'
	Our reserve for losses and loss expenses represents an estimate of the unpaid portion of our ultimate liability for losses and loss expenses for (re)insured events that have occurred at or before the balance sheet date. The balance reflects both claims that have been reported to us (“case reserves”) and claims that have been incurred but not yet reported to us (“IBNR”). These amounts are reduced for estimated amounts of salvage and subrogation recoveries.
	We review our reserve for losses and loss expenses on a quarterly basis. Case reserves are primarily established based on amounts reported from insureds and/or their brokers. Management estimates IBNR after reviewing detailed actuarial analyses and applying informed judgment regarding qualitative factors that may not be fully captured in the actuarial estimates. A variety of actuarial methods are utilized in this process, including the Expected Loss Ratio, Bornhuetter-Ferguson and Chain Ladder methods. Our estimate is highly dependent on management’s judgment as to which method(s) are most appropriate for a particular accident year and class of business. Our historical claims data is often supplemented with industry benchmarks when applying these methodologies.
	Any adjustments to our previous reserve for losses and loss expenses estimates are recognized in the period they are determined. While we believe that our reserves for losses and loss expenses are adequate, this estimate requires significant judgment and new information, events or circumstances may result in ultimate losses that are materially greater or less than provided for in the Consolidated Balance Sheets.
Reinsurance [Policy Text Block]	'
	In the normal course of business, we purchase reinsurance protection to limit our ultimate losses from catastrophic events and to reduce our loss aggregation risk. The premiums paid to our reinsurers (i.e. premiums ceded) are expensed over the coverage period. Prepaid reinsurance premiums represent the portion of premiums ceded applicable to the unexpired term of the contracts in force. Reinstatement-related premiums ceded are recorded at the time a loss event occurs and our coverage limits for the remaining life of a contract are reinstated under pre-defined contract terms; such premiums are expensed over the remaining risk period.
	Reinsurance recoverable related to our case reserves is estimated on a case-by-case basis by applying the terms of any applicable reinsurance coverage to our individual case reserve estimates. Our estimate of reinsurance recoverable related to our IBNR reserves is generally developed as part of our loss reserving process.
	Our reinsurance recoverable is presented net of a provision for uncollectible amounts, reflecting the amount we believe will ultimately not be recovered due to reinsurer insolvency, contractual disputes and/or some other reason. We apply case-specific provisions against certain recoveries that we deem unlikely to be collected in full. In addition, we use a default analysis to estimate our provision for uncollectible amounts on the remainder of the balance.
	The estimates of our reinsurance recoverable and the associated provision require management’s judgment and are reviewed in detail on a quarterly basis. Any adjustments to amounts recognized in prior periods are reported in our net losses and loss expenses in the Consolidated Statements of Operations for the period when the adjustments were identified. The charge-off of amounts previously reserved as uncollectible is also considered on a case-by-case basis as part of this quarterly process.
Foreign exchange [Policy Text Block]	'
	The Company’s reporting currency is the U.S. dollar. In translating the financial statements of our subsidiaries or branches where the functional currency is other than the U.S. dollar, assets and liabilities are converted into U.S. dollars using the rates of exchange in effect at the balance sheet dates and revenues and expenses are converted using the weighted average foreign exchange rates for the period. The effect of translation adjustments is reported as a separate component of AOCI in shareholders’ equity.
	In recording foreign currency transactions, revenue and expense items are converted to the relevant functional currency at the exchange rate prevailing at the transaction date. Assets and liabilities originating in currencies other than the functional currency are translated into the functional currency at the rates of exchange in effect at the balance sheet date. The resulting foreign currency gains or losses are recognized in the Consolidated Statements of Operations, with the exception of those related to foreign-denominated available for sale investments. For these investments, exchange rate fluctuations represent an unrealized appreciation/depreciation in the value of the securities and are included in the related component of AOCI.
Share-based compensation [Policy Text Block]	'
	The Company is authorized to issue restricted stock awards and units, stock options and other equity-based awards to its employees and directors. The fair value of service-based awards is measured at the grant date, with the associated expense recognized on a straight-line basis over the service period. The fair value of performance-based awards ("PSUs") is measured at the grant date based on pre-established targets relating to certain performance based measures achieved by the Company, with the associated expense recognized on a straight-line basis over the applicable performance and vesting period. The compensation expense for PSUs is subject to a periodic review and adjustment taking into account actual performance of the Company. The fair value of the liability associated with cash-settled awards is re-measured at each balance sheet date, with the effects recognized as an increase or decrease to share-based compensation expense for the period. Forfeiture benefits are estimated at the time of grant and incorporated in the determination of share-based compensation expense.
Derivatives instruments [Policy Text Block]	'
	Derivative Instruments not Designated as Hedging Instruments
	We may enter into derivative instruments such as futures, options, interest rate swaps and foreign currency forward contracts as part of our overall foreign currency risk management strategy, to obtain exposure to a particular financial market or for yield enhancement. During 2013, we began to write derivative based risk management products designed to address weather and commodity price risks, with the objective of generating profits on a portfolio basis. From time to time we may also enter into (re)insurance contracts that meet the FASB’s definition of a derivative contract.
	We measure all derivative instruments at fair value (see Note 6 – Fair Value Measurements) and recognize them as either assets or liabilities in the Consolidated Balance Sheets. Subsequent changes in fair value and any realized gains or losses are recognized in the Consolidated Statements of Operations.
	Derivative Instruments Designated as Hedging Instruments
	We may designate a currency derivative as a hedge of foreign exchange rate-related movements in the fair value of certain investment portfolios. This is referred to as a fair value hedge. Changes in the fair value of the designated fair value hedge, along with the changes in the fair value of the hedged asset attributable to the hedged risk, are recorded in net realized investment gains (losses) in the Consolidated Statements of Operations, along with any hedge ineffectiveness.
	To qualify for hedge accounting treatment, a derivative must be highly effective in mitigating the designated changes in value of the hedged item. Further, the hedge relationship must be designated and formally documented at the inception, detailing the particular risk management objective and strategy for the hedge, including the item and risk that is being hedged, the derivative that is being used, and how effectiveness will be assessed. We formally measure the hedge effectiveness at inception and on an ongoing basis. We evaluate the effectiveness on a retrospective and prospective basis, using the period-to-period dollar offset method. Using this method, if the hedge correlation is within the range of 80% to 125%, we consider the hedge effective and apply hedge accounting. Cash flows from derivative instruments designated as hedging instruments are presented as operating activities in the Consolidated Statements of Cash Flows.
Goodwill and intangible assets [Policy Text Block]	'
	We classify intangible assets into three categories: (1) intangible assets with finite lives subject to amortization, (2) intangible assets with indefinite lives not subject to amortization, and (3) goodwill.
	We amortize intangible assets with finite lives over their estimated useful lives in proportion to the estimated economic benefits of the intangible assets. We also test these assets for impairment if circumstances indicate that the carrying value may not be fully recoverable. Such circumstances may include an economic downturn in a geographic market or a change in the assessment of future operations. If, as a result of such an evaluation, we determine that the carrying value of the finite-lived intangible assets is not recoverable, the value of the assets will be reduced to fair value with the difference being expensed in the Consolidated Statements of Operations.
	Our intangible assets with indefinite lives include licenses held by certain subsidiaries in various jurisdictions that allow such subsidiaries to write insurance and/or reinsurance business. These intangible assets are carried at or below estimated fair value and are tested annually for impairment, either qualitatively or quantitatively, and between annual tests if events or changes in circumstances indicate that it is more likely than not that the asset is impaired.
	We have recorded goodwill in connection with certain acquisitions. Goodwill represents the excess of the cost of acquisitions over the fair value of the net assets acquired and is assigned to applicable reporting unit(s) on the acquisition date, based upon the expected benefit to be received by the reporting unit. We determine the expected benefit based on several factors, including the purpose of the business combination, our strategy subsequent to the business combination and the structure of the acquired company subsequent to the business combination. Goodwill is not subject to amortization. We test goodwill for potential impairment during the fourth quarter each year and between annual tests if an event occurs or circumstances change that would more likely than not reduce the fair value of a reporting unit to a level below its carrying amount. We have the option to first make this assessment on a qualitative basis. Should we choose to forgo this option, or if our qualitative assessment indicates that fair value is more likely than not below carrying value, we conduct a quantitative two-step impairment evaluation at the reporting unit level. First, we identify potential impairment by comparing the estimated fair values of the reporting units to estimated book values, including goodwill. The fair value of each reporting unit is derived based upon valuation techniques and assumptions that we believe market participants would use to value our business. The estimated fair values are generally determined utilizing methodologies that incorporate discounted cash flow analyses. The values derived from the analyses are then compared to recent market transactions for reasonableness. We derive the net book value of our reporting units by estimating the amount of shareholders’ equity required to support the activities of each reporting unit. If the estimated fair value of a reporting unit exceeds the estimated book value, goodwill is not considered impaired. If the book value exceeds the estimated fair value, the second step compares the implied fair value of the reporting unit’s goodwill with the carrying amount of the goodwill in order to determine the magnitude of impairment to be recognized. The implied fair value of goodwill is determined by deducting the fair value of a reporting unit’s identifiable assets and liabilities from the fair value of the reporting unit as a whole. The excess of the carrying value of goodwill above the implied goodwill, if any, would be recognized as an impairment charge in the Consolidated Statements of Operations.
Income taxes [Policy Text Block]	'
	Certain subsidiaries and branches of the Company operate in jurisdictions where they are subject to taxation. Current and deferred income taxes are charged or credited to net income, or in certain cases to AOCI, based upon enacted tax laws and rates applicable in the relevant jurisdiction in the period in which the tax becomes accruable or realizable. Deferred income taxes are provided for all temporary differences between the bases of assets and liabilities used in the Consolidated Balance Sheets and those used in the various jurisdictional tax returns. When our assessment indicates that it is more likely than not that a portion of a deferred tax asset will not be realized in the foreseeable future, a valuation allowance against deferred tax assets is recorded. We recognize the tax benefits of uncertain tax positions only when the position is more-likely-than-not to be sustained upon audit by the relevant taxing authorities.
Treasury shares [Policy Text Block]	'
	Common shares repurchased by the Company and not subsequently cancelled are classified as treasury shares and are recorded at cost. This results in a reduction of shareholders’ equity in the Consolidated Balance Sheets. When shares are reissued from treasury, we use the average cost method to determine the cost of the reissued shares. Gains on sales/reissuances of treasury shares are credited to additional paid-in capital, while losses are charged to additional paid-in capital to the extent that previous net gains from reissued treasury shares were included therein; otherwise losses are charged to retained earnings.
New accounting standards adopted [Policy Text Block]	'
	Balance Sheet Offsetting
	Effective January 1, 2013, we adopted Financial Accounting Standards Board ("FASB") guidance requiring additional disclosures about financial instruments and derivative instruments that are either: (1) offset for balance sheet presentation purposes or (2) subject to an enforceable master netting arrangement or similar arrangement, regardless of whether they are offset for balance sheet presentation purposes. The disclosure requirements of this guidance are limited to derivatives, repurchase agreements and reverse repurchase agreements, and securities borrowing/lending transactions. As this guidance is disclosure-related only and did not amend existing balance sheet offsetting guidance, adoption did not impact our results of operations, financial condition or liquidity. The additional disclosures are provided in Note 7 - Derivative Instruments.
	Reporting Amounts Reclassified Out of Accumulated Other Comprehensive Income ("AOCI")
	Effective January 1, 2013, we adopted FASB guidance requiring additional disclosures about reclassification adjustments from AOCI. As this guidance is disclosure-related only and did not amend existing guidance on the reporting of net income available to common shareholders or other comprehensive income, adoption did not impact our results of operations, financial condition or liquidity. The additional disclosures are provided in Note 19 - Other Comprehensive Income (Loss).

SEGMENT_INFORMATION_TABLES

SEGMENT INFORMATION (TABLES)	12 Months Ended
	Dec. 31, 2013
Segment Reporting [Abstract]	'
UNDERWRITING RESULTS OF REPORTABLE SEGMENTS [Table Text Block]	'
		At and year ended December 31, 2013	Insurance			Reinsurance			Total
		Gross premiums written	$	2,559,138		$	2,137,903		$	4,697,041
		Net premiums written	1,813,538			2,114,662			3,928,200
		Net premiums earned	1,722,762			1,984,303			3,707,065
		Other insurance related income	2,436			1,988			4,424
		Net losses and loss expenses	(1,050,402		)	(1,083,793		)	(2,134,195		)
		Acquisition costs	(242,363		)	(421,828		)	(664,191		)
		General and administrative expenses	(347,684		)	(137,450		)	(485,134		)
		Underwriting income	$	84,749		$	343,220		427,969
		Corporate expenses							(90,256		)
		Net investment income							409,312
		Net realized investment gains							75,564
		Foreign exchange losses							(26,143		)
		Interest expense and financing costs							(61,979		)
		Income before income taxes							$	734,467
		Net loss and loss expense ratio	61		%	54.6		%	57.6		%
		Acquisition cost ratio	14.1		%	21.3		%	17.9		%
		General and administrative expense ratio	20.1		%	6.9		%	15.5		%
		Combined ratio	95.2		%	82.8		%	91		%
		Goodwill and intangible assets	$	89,528		$	—		$	89,528
		At and year ended December 31, 2012	Insurance			Reinsurance			Total
		Gross premiums written	$	2,309,481		$	1,830,162		$	4,139,643
		Net premiums written	1,522,245			1,815,211			3,337,456
		Net premiums earned	1,558,058			1,857,405			3,415,463
		Other insurance related income	2,676			—			2,676
		Net losses and loss expenses	(953,564		)	(1,142,464		)	(2,096,028		)
		Acquisition costs	(226,859		)	(400,794		)	(627,653		)
		General and administrative expenses	(314,834		)	(116,487		)	(431,321		)
		Underwriting income	$	65,477		$	197,660		263,137
		Corporate expenses							(129,660		)
		Net investment income							380,957
		Net realized investment gains							127,469
		Foreign exchange losses							(29,512		)
		Interest expense and financing costs							(61,863		)
		Income before income taxes							$	550,528
		Net loss and loss expense ratio	61.2		%	61.5		%	61.4		%
		Acquisition cost ratio	14.6		%	21.6		%	18.4		%
		General and administrative expense ratio	20.2		%	6.3		%	16.4		%
		Combined ratio	96		%	89.4		%	96.2		%
		Goodwill and intangible assets	$	97,493		$	—		$	97,493
		At and year ended December 31, 2011	Insurance			Reinsurance			Total
		Gross premiums written	$	2,121,829		$	1,974,324		$	4,096,153
		Net premiums written	1,466,134			1,953,300			3,419,434
		Net premiums earned	1,429,687			1,885,274			3,314,961
		Other insurance related income	2,396			—			2,396
		Net losses and loss expenses	(919,319		)	(1,755,733		)	(2,675,052		)
		Acquisition costs	(199,583		)	(387,886		)	(587,469		)
		General and administrative expenses	(278,147		)	(103,915		)	(382,062		)
		Underwriting income (loss)	$	35,034		$	(362,260	)	(327,226		)
		Corporate expenses							(77,089		)
		Net investment income							362,430
		Net realized investment gains							121,439
		Foreign exchange gains							44,582
		Interest expense and financing costs							(62,598		)
		Income before income taxes							$	61,538
		Net loss and loss expense ratio	64.3		%	93.1		%	80.7		%
		Acquisition cost ratio	14		%	20.6		%	17.7		%
		General and administrative expense ratio	19.4		%	5.5		%	13.9		%
		Combined ratio	97.7		%	119.2		%	112.3		%
		Goodwill and intangible assets	$	99,590		$	—		$	99,590
GROSS PREMIUMS WRITTEN BY GEOGRAPHICAL LOCATION OF SUBSIDIARIES [Table Text Block]	'
		Year ended December 31,	2013			2012			2011
		Bermuda	$	718,904		$	684,588		$	822,237
		Europe	1,699,748			1,561,701			1,493,692
		United States	2,278,389			1,893,354			1,780,224
		Total gross premium written	$	4,697,041		$	4,139,643		$	4,096,153
NET PREMIUMS EARNED BY SEGMENT AND LINE OF BUSINESS [Table Text Block]	'
		Year ended December 31,	2013			2012			2011
		Insurance
		Property	$	462,364		$	408,943		$	385,291
		Marine	179,057			171,165			152,123
		Terrorism	39,298			38,605			35,213
		Aviation	48,489			60,363			70,681
		Credit and political risk	68,192			87,103			97,680
		Professional lines	586,200			563,500			536,238
		Liability	110,623			86,873			89,555
		Accident & health	228,539			141,506			62,906
		Total Insurance	1,722,762			1,558,058			1,429,687
		Reinsurance
		Catastrophe	380,199			375,088			456,858
		Property	350,970			351,470			356,022
		Professional lines	304,754			297,726			281,025
		Credit and surety	279,943			277,185			263,912
		Motor	221,844			237,006			202,830
		Liability	234,736			220,874			230,872
		Agriculture	126,490			17,116			15,031
		Engineering	66,243			68,402			65,727
		Other	19,124			12,538			12,997
		Total Reinsurance	1,984,303			1,857,405			1,885,274
		Total	$	3,707,065		$	3,415,463		$	3,314,961

GOODWILL_AND_INTANGIBLE_ASSETS1

GOODWILL AND INTANGIBLE ASSETS (TABLES)	12 Months Ended
	Dec. 31, 2013
Goodwill and Intangible Assets Disclosure [Abstract]	'
SCHEDULE OF GOODWILL AND INTANGIBLE ASSETS [Table Text Block]	'
			Goodwill			Intangible		Intangible			Total
						assets with an		assets with a
						indefinite life		finite life
		Net balance at December 31, 2011	$	49,350		$	26,036	$	24,204		$	99,590
		Amortization	—			—		(2,618		)	(2,618		)
		Foreign currency translation adjustment	285			—		236			521
		Net balance at December 31, 2012	49,635			26,036		21,822			97,493
		Amortization	—			—		(2,233		)	(2,233		)
		Foreign currency translation adjustment	(3,213		)	—		(2,519		)	(5,732		)
		Net balance at December 31, 2013	$	46,422		$	26,036	$	17,070		$	89,528
		Gross balance at December 31, 2013	$	42,237		$	26,036	$	35,596		$	103,869
		Accumulated amortization	—			—		(23,601		)	(23,601		)
		Foreign currency translation adjustment	4,185			—		5,075			9,260
		Net balance at December 31, 2013	$	46,422		$	26,036	$	17,070		$	89,528

INVESTMENTS_TABLES

INVESTMENTS (TABLES)	12 Months Ended
	Dec. 31, 2013
Investments, Debt and Equity Securities [Abstract]	'
AMORTIZED COST/COST AND FAIR VALUES OF FIXED MATURITIES AND EQUITIES [Table Text Block]	'
			Amortized			Gross				Gross			Fair			Non-credit
			Cost or			Unrealized				Unrealized			Value			OTTI
			Cost			Gains				Losses						in AOCI(5)
		At December 31, 2013
		Fixed maturities
		U.S. government and agency	$	1,421,245		$	1,405			$	(33,952	)	$	1,388,698		$	—
		Non-U.S. government	1,208,384			17,990				(49,992		)	1,176,382			—
		Corporate debt	3,533,585			84,881				(10,228		)	3,608,238			—
		Agency RMBS(1)	2,485,139			21,979				(58,291		)	2,448,827			—
		CMBS(2)	790,095			11,285				(3,966		)	797,414			—
		Non-Agency RMBS	65,590			2,375				(398		)	67,567			(868		)
		ABS(3)	955,274			6,871				(8,694		)	953,451			—
		Municipals(4)	1,527,834			32,432				(14,516		)	1,545,750			—
		Total fixed maturities	$	11,987,146		$	179,218			$	(180,037	)	$	11,986,327		$	(868	)
		Equity securities
		Common stocks	345,759			98,742				(6,183		)	438,318
		Exchange-traded funds	106,762			32,085				—			138,847
		Non-U.S. bond mutual funds	113,698			11,124				—			124,822
		Total equity securities	$	566,219		$	141,951			$	(6,183	)	$	701,987
		At December 31, 2012
		Fixed maturities
		U.S. government and agency	$	1,413,520		$	9,484			$	(119	)	$	1,422,885		$	—
		Non-U.S. government	1,076,501			30,276				(2,201		)	1,104,576			—
		Corporate debt	3,746,616			135,658				(5,892		)	3,876,382			—
		Agency RMBS(1)	2,594,180			67,398				(1,670		)	2,659,908			—
		CMBS(2)	814,211			25,999				(126		)	840,084			—
		Non-Agency RMBS	93,266			2,503				(570		)	95,199			(884		)
		ABS(3)	639,614			10,774				(7,182		)	643,206			—
		Municipals(4)	1,227,764			58,770				(725		)	1,285,809			—
		Total fixed maturities	$	11,605,672		$	340,862			$	(18,485	)	$	11,928,049		$	(884	)
		Equity securities
		Common stocks	398,975			51,821				(7,398		)	443,398
		Exchange-traded funds	109,434			9,727				—			119,161
		Non-U.S. bond mutual funds	99,897			4,092				—			103,989
		Total equity securities	$	608,306		$	65,640			$	(7,398	)	$	666,548
	-1	Residential mortgage-backed securities (RMBS) originated by U.S. agencies.
	-2	Commercial mortgage-backed securities (CMBS).
	-3	Asset-backed securities (ABS) include debt tranched securities collateralized primarily by auto loans, student loans, credit cards, and other asset types. This asset class also includes collateralized loan obligations (CLOs) and collateralized debt obligations (CDOs).
	-4	Municipals include bonds issued by states, municipalities and political subdivisions.
	-5	Represents the non-credit component of the other-than-temporary impairment (OTTI) losses, adjusted for subsequent sales of securities. It does not include the change in fair value subsequent to the impairment measurement date.
CONTRACTUAL MATURITIES OF FIXED MATURITIES [Table Text Block]	'
			Amortized			Fair				% of Total
			Cost			Value				Fair Value
		At December 31, 2013
		Maturity
		Due in one year or less	$	710,079		$	717,052			5.9	%
		Due after one year through five years	5,030,728			5,116,060				42.7	%
		Due after five years through ten years	1,852,877			1,791,835				14.9	%
		Due after ten years	97,364			94,121				0.8	%
			7,691,048			7,719,068				64.3	%
		Agency RMBS	2,485,139			2,448,827				20.4	%
		CMBS	790,095			797,414				6.7	%
		Non-Agency RMBS	65,590			67,567				0.6	%
		ABS	955,274			953,451				8	%
		Total	$	11,987,146		$	11,986,327			100	%
		At December 31, 2012
		Maturity
		Due in one year or less	$	651,111		$	657,045			5.5	%
		Due after one year through five years	4,880,039			4,989,151				41.8	%
		Due after five years through ten years	1,847,295			1,951,569				16.4	%
		Due after ten years	85,956			91,887				0.8	%
			7,464,401			7,689,652				64.5	%
		Agency RMBS	2,594,180			2,659,908				22.3	%
		CMBS	814,211			840,084				7	%
		Non-Agency RMBS	93,266			95,199				0.8	%
		ABS	639,614			643,206				5.4	%
		Total	$	11,605,672		$	11,928,049			100	%
FIXED MATURITIES AND EQUITIES IN AN UNREALIZED LOSS POSITION [Table Text Block]	'
			12 months or greater							Less than 12 months						Total
			Fair			Unrealized				Fair			Unrealized			Fair			Unrealized
			Value			Losses				Value			Losses			Value			Losses
		At December 31, 2013
		Fixed maturities
		U.S. government and agency	$	—		$	—			$	982,307		$	(33,952	)	$	982,307		$	(33,952	)
		Non-U.S. government	35,577			(3,430		)		420,622			(46,562		)	456,199			(49,992		)
		Corporate debt	27,696			(802		)		606,592			(9,426		)	634,288			(10,228		)
		Agency RMBS	144,468			(5,247		)		1,478,527			(53,044		)	1,622,995			(58,291		)
		CMBS	13,319			(116		)		298,863			(3,850		)	312,182			(3,966		)
		Non-Agency RMBS	4,287			(315		)		5,319			(83		)	9,606			(398		)
		ABS	37,765			(2,941		)		553,803			(5,753		)	591,568			(8,694		)
		Municipals	8,408			(615		)		543,474			(13,901		)	551,882			(14,516		)
		Total fixed maturities	$	271,520		$	(13,466	)		$	4,889,507		$	(166,571	)	$	5,161,027		$	(180,037	)
		Equity securities
		Common stocks	$	3,499		$	(398	)		$	48,828		$	(5,785	)	$	52,327		$	(6,183	)
		Total equity securities	$	3,499		$	(398	)		$	48,828		$	(5,785	)	$	52,327		$	(6,183	)
		At December 31, 2012
		Fixed maturities
		U.S. government and agency	$	—		$	—			$	119,730		$	(119	)	$	119,730		$	(119	)
		Non-U.S. government	44,568			(1,453		)		153,134			(748		)	197,702			(2,201		)
		Corporate debt	95,511			(2,947		)		451,651			(2,945		)	547,162			(5,892		)
		Agency RMBS	9,557			(148		)		521,400			(1,522		)	530,957			(1,670		)
		CMBS	1,749			(16		)		69,615			(110		)	71,364			(126		)
		Non-Agency RMBS	11,026			(537		)		115			(33		)	11,141			(570		)
		ABS	99,514			(7,034		)		39,296			(148		)	138,810			(7,182		)
		Municipals	6,386			(270		)		77,766			(455		)	84,152			(725		)
		Total fixed maturities	$	268,311		$	(12,405	)		$	1,432,707		$	(6,080	)	$	1,701,018		$	(18,485	)
		Equity securities
		Common stocks	$	11,554		$	(1,793	)		$	95,697		$	(5,605	)	$	107,251		$	(7,398	)
		Total equity securities	$	11,554		$	(1,793	)		$	95,697		$	(5,605	)	$	107,251		$	(7,398	)
PORTFOLIO OF OTHER INVESTMENTS [Table Text Block]	'
			Fair Value						Redemption Frequency		Redemption
									(if currently eligible)		Notice Period
		At December 31, 2013
		Long/short equity funds	$	425,444		41	%		Monthly, Quarterly, Semi-annually		30-60 days
		Multi-strategy funds	285,155			27	%		Quarterly, Semi-annually		60-95 days
		Event-driven funds	190,458			18	%		Quarterly, Annually		45-60 days
		Leveraged bank loan funds	48,753			5	%		Quarterly		65 days
		Direct lending funds	22,134			2	%		n/a		n/a
		CLO - Equities	73,866			7	%		n/a		n/a
		Total other investments	$	1,045,810		100	%
		At December 31, 2012
		Long/short equity funds	$	302,680		36	%		Monthly, Quarterly, Semi-annually		30-60 days
		Multi-strategy funds	244,075			29	%		Quarterly, Semi-annually		60-95 days
		Event-driven funds	171,479			20	%		Quarterly, Annually		45-95 days
		Leveraged bank loan funds	62,768			8	%		Quarterly		65 days
		Direct lending funds	—			—	%		n/a		n/a
		CLO - Equities	62,435			7	%		n/a		n/a
		Total other investments	$	843,437		100	%
	n/a – not applicable
NET INVESTMENT INCOME [Table Text Block]	'
		Year ended December 31,	2013			2012				2011
		Fixed maturities	$	293,609		$	304,400			$	337,616
		Other investments	128,814			87,660				31,856
		Equity securities	10,897			11,904				11,186
		Cash and cash equivalents	6,337			4,528				5,697
		Short-term investments	1,181			596				1,592
		Gross investment income	440,838			409,088				387,947
		Investment expenses	(31,526		)	(28,131		)		(25,517		)
		Net investment income	$	409,312		$	380,957			$	362,430
NET REALIZED INVESTMENT GAINS (LOSSES) [Table Text Block]	'
		Year ended December 31,	2013			2012				2011
		Gross realized gains
		Fixed maturities and short-term investments(1)	$	120,932		$	242,082			$	243,296
		Equities	54,564			36,411				16,992
		Gross realized gains	175,496			278,493				260,288
		Gross realized losses
		Fixed maturities and short-term investments(1)	(87,894		)	(101,844		)		(108,490		)
		Equities	(10,407		)	(23,530		)		(14,526		)
		Gross realized losses	(98,301		)	(125,374		)		(123,016		)
		Net OTTI recognized in earnings	(9,362		)	(24,234		)		(15,861		)
		Change in fair value of investment derivatives(2)	7,731			(9,170		)		4,431
		Fair value hedges(2)	—			7,754				(4,403		)
		Net realized investment gains	$	75,564		$	127,469			$	121,439
	-1	Includes $37 million of gains in 2012 and $11 million of losses in 2011 relating to previously unrealized foreign exchange currency amounts on the hedged fixed maturity portfolios. The hedged portfolio was sold and all associated foreign exchange contracts were fully settled during 2012 so there is no impact on the 2013 figures.
	-2	Refer to Note 7 – Derivative Instruments
OTTI RECOGNIZED IN EARNINGS BY ASSET CLASS [Table Text Block]	'
		Year ended December 31,	2013			2012				2011
		Fixed maturities:
		Non-U.S. government	$	120		$	3,281			$	—
		Corporate debt	5,802			1,821				1,954
		Non-Agency RMBS	57			2,016				717
		ABS	129			795				61
		Municipals	639			—				483
			6,747			7,913				3,215
		Equity Securities
		Common stocks	2,092			7,318				12,646
		Exchange-traded funds	523			9,003				—
			2,615			16,321				12,646
		Total OTTI recognized in earnings	$	9,362		$	24,234			$	15,861
ROLL FORWARD OF CREDIT LOSSES FOR WHICH A PORTION OF OTTI RECOGNIZED IN AOCI [Table Text Block]	'
		Year ended December 31,	2013			2012
		Balance at beginning of period	$	1,809		$	2,061
		Credit impairments recognized on securities not previously impaired	—			—
		Additional credit impairments recognized on securities previously impaired	—			—
		Change in timing of future cash flows on securities previously impaired	—			—
		Intent to sell of securities previously impaired	—			—
		Securities sold/redeemed/matured	(215		)	(252		)
		Balance at end of period	$	1,594		$	1,809
SIGNIFICANT INPUTS TO ESTIMATE CREDIT LOSSES FOR CLO - DEBT [Table Text Block]	'
		At December 31,	2013		2012
		Default rate	4.00%		4.00%
		Loss severity rate	53.50%		53.50%
		Collateral spreads	2.7% - 3.5%		2.5% - 3.7%
RESTRICTED INVESTMENTS [Table Text Block]	'
		At December 31,		2013			2012
		Collateral in Trust for inter-company agreements		$	2,261,081		$	2,134,931
		Collateral for secured letter of credit facility		777,828			470,062
		Collateral in Trust for third party agreements		276,839			245,539
		Securities on deposit with regulatory authorities		58,327			59,456
		Total restricted investments		$	3,374,075		$	2,909,988

FAIR_VALUE_MEASUREMENTS_TABLES

FAIR VALUE MEASUREMENTS (TABLES)	12 Months Ended
	Dec. 31, 2013
Fair Value Disclosures [Abstract]	'
FINANCIAL INSTRUMENTS MEASURED AT FAIR VALUE ON A RECURRING BASIS [Table Text Block]	'
			Quoted Prices in			Significant			Significant			Total Fair
			Active Markets for			Other Observable			Unobservable			Value
			Identical Assets			Inputs			Inputs
			(Level 1)			(Level 2)			(Level 3)
		At December 31, 2013
		Assets
		Fixed maturities
		U.S. government and agency	$	1,119,632		$	269,066		$	—		$	1,388,698
		Non-U.S. government	—			1,176,382			—			1,176,382
		Corporate debt	—			3,608,238			—			3,608,238
		Agency RMBS	—			2,448,827			—			2,448,827
		CMBS	—			793,396			4,018			797,414
		Non-Agency RMBS	—			67,567			—			67,567
		ABS	—			922,652			30,799			953,451
		Municipals	—			1,545,750			—			1,545,750
			1,119,632			10,831,878			34,817			11,986,327
		Equity securities
		Common stocks	438,318			—			—			438,318
		Exchange-traded funds	138,847			—			—			138,847
		Non-U.S. bond mutual funds	—			124,822			—			124,822
			577,165			124,822			—			701,987
		Other investments
		Hedge funds	—			488,755			461,055			949,810
		Direct lending funds	—			—			22,134			22,134
		CLO-Equities	—			—			73,866			73,866
			—			488,755			557,055			1,045,810
		Short-term investments	—			46,212			—			46,212
		Derivative instruments (see Note 7)	—			6,824			984			7,808
		Total Assets	$	1,696,797		$	11,498,491		$	592,856		$	13,788,144
		Liabilities
		Derivative instruments (see Note 7)	$	—		$	1,152		$	815		$	1,967
		Cash settled awards (see Note 16)	—			8,693			—			8,693
		Total Liabilities	$	—		$	9,845		$	815		$	10,660
		At December 31, 2012
		Assets
		Fixed maturities
		U.S. government and agency	$	1,094,220		$	328,665		$	—		$	1,422,885
		Non-U.S. government	—			1,104,576			—			1,104,576
		Corporate debt	—			3,874,832			1,550			3,876,382
		Agency RMBS	—			2,659,908			—			2,659,908
		CMBS	—			835,788			4,296			840,084
		Non-Agency RMBS	—			94,089			1,110			95,199
		ABS	—			579,231			63,975			643,206
		Municipals	—			1,285,809			—			1,285,809
			1,094,220			10,762,898			70,931			11,928,049
		Equity securities
		Common stocks	443,398			—			—			443,398
		Exchange-traded funds	119,161			—			—			119,161
		Non-U.S. bond mutual funds	—			103,989			—			103,989
			562,559			103,989			—			666,548
		Other investments
		Hedge funds	—			421,006			359,996			781,002
		Direct lending funds	—			—			—			—
		CLO-Equities	—			—			62,435			62,435
			—			421,006			422,431			843,437
		Short-term investments	—			108,860			—			108,860
		Derivative instruments (see Note 7)	—			5,838			—			5,838
		Total Assets	$	1,656,779		$	11,402,591		$	493,362		$	13,552,732
		Liabilities
		Derivative instruments (see Note 7)	$	—		$	3,737		$	—		$	3,737
		Cash settled awards (see Note 16)	—			—			—			—
		Total Liabilities	$	—		$	3,737		$	—		$	3,737
LEVEL 3 FAIR VALUE MEASUREMENT INPUTS [Table Text Block]	'
			Fair Value		Valuation Technique	Unobservable Input	Range	Weighted
								Average
		ABS - CLO Debt	$	29,944	Discounted cash flow	Credit spreads	3.3% - 4.6%	3.70%
						Illiquidity discount (1)	5%	5%
			855		Broker-dealer quote	n/a	n/a	n/a
			$	30,799
		Other investments - CLO Equities	$	39,706	Discounted cash flow	Default rates	4.0% - 5.0%	4.40%
						Loss severity rate	53.50%	53.50%
						Collateral spreads	2.6% - 3.4%	3.30%
						Estimated maturity dates	2.1 - 4.6 years	4.2 years
			34,160		Net asset value	n/a	n/a	n/a
			$	73,866
		Derivatives - Weather derivatives, net	$	169	Simulation model	Weather curve	525 - 4,750(2)	n/a (3)
						Weather standard deviation	94 - 290(2)	n/a (3)
	(1) Judgmentally determined based on limited trades of similar securities observed in the secondary markets.
	(2) Measured in Heating Degree Days ("HDD") which is the number of degrees the daily temperature is below a reference temperature. The cumulative HDD for the duration of the derivatives contract is compared to the strike value to determine the necessary settlement.
	-3	Due to the diversity of the portfolio, the range of unobservable inputs is widespread; therefore, presentation of a weighted average is not useful. Weather parameters may include various temperature and/or precipitation measures that will naturally vary by geographic location of each counterparty's operations.
CHANGES IN LEVEL 3 FINANCIAL INSTRUMENTS MEASURED AT FAIR VALUE ON A RECURRING BASIS [Table Text Block]	'
			Opening			Transfers			Transfers			Included in			Included			Purchases			Sales			Settlements/			Closing		Change in
			Balance			into			out of			earnings (1)			in OCI (2)									Distributions			Balance		unrealized
						Level 3			Level 3																				investment
																													gain/loss (3)
		Year ended December 31, 2013
		Fixed maturities
		Corporate debt	$	1,550		$	—		$	—		$	1,550		$	—		$	—		$	—		$	(3,100	)	$	—	$	—
		Non-Agency RMBS	1,110			—			(1,222		)	—			135			—			—			(23		)	—		—
		CMBS	4,296			—			—			—			(278		)	—			—			—			4,018		—
		ABS	63,975			—			—			(111		)	1,794			—			—			(34,859		)	30,799		—
			70,931			—			(1,222		)	1,439			1,651			—			—			(37,982		)	34,817		—
		Other investments
		Hedge funds	359,996			—			—			58,293			—			86,138			—			(43,372		)	461,055		58,293
		Direct lending funds	—			—			—			(125		)	—			22,317			—			(58		)	22,134		(125		)
		CLO-Equities	62,435			—			—			27,898			—			34,016			—			(50,483		)	73,866		27,898
			422,431			—			—			86,066			—			142,471			—			(93,913		)	557,055		86,066
		Other assets
		Derivative instruments	—			—			—			2,084			—			(1,100		)	—			—			984		2,084
			—			—			—			2,084			—			(1,100		)	—			—			984		2,084
		Total assets	$	493,362		$	—		$	(1,222	)	$	89,589		$	1,651		$	141,371		$	—		$	(131,895	)	$	592,856	$	88,150
		Other liabilities
		Derivative instruments	—			—			—			98			—			717			—			—			815		98
		Total liabilities	$	—		$	—		$	—		$	98		$	—		$	717		$	—		$	—		$	815	$	98
		Year ended December 31, 2012
		Fixed maturities
		Corporate debt	$	1,550		$	—		$	—		$	—		$	—		$	—		$	—		$	—		$	1,550	$	—
		Non-Agency RMBS	—			1,110			—			—			—			—			—			—			1,110		—
		CMBS	—			4,296			—			—			—			—			—			—			4,296		—
		ABS	49,328			10,539			—			—			5,112			—			—			(1,004		)	63,975		—
			50,878			15,945			—			—			5,112			—			—			(1,004		)	70,931		—
		Other investments
		Hedge funds	346,244			—			(9,435		)	33,301			—			—			(2,835		)	(7,279		)	359,996		33,301
		Direct lending funds	—			—			—			—			—			—			—			—			—		—
		CLO-Equities	66,560			—			—			31,108			—			—			—			(35,233		)	62,435		31,108
			412,804			—			(9,435		)	64,409			—			—			(2,835		)	(42,512		)	422,431		64,409
		Other assets
		Derivative instruments	—			—			—			—			—			—			—			—			—		—
			—			—			—			—			—			—			—			—			—		—
		Total assets	$	463,682		$	15,945		$	(9,435	)	$	64,409		$	5,112		$	—		$	(2,835	)	$	(43,516	)	$	493,362	$	64,409
		Other liabilities
		Derivative instruments	—			—			—			—			—			—			—			—			—		—
		Total liabilities	$	—		$	—		$	—		$	—		$	—		$	—		$	—		$	—		$	—	$	—
	-1	Gains and losses included in earnings on fixed maturities are included in net realized investment gains (losses). Gains and (losses) included in earnings on other investments are included in net investment income. Gains (losses) on weather derivatives included in earnings are included in other insurance-related income.
	-2	Gains and losses included in other comprehensive income (“OCI”) on fixed maturities are included in unrealized gains (losses) arising during the period.
	-3	Change in unrealized investment gain/(loss) relating to assets held at the reporting date.

DERIVATIVE_INSTRUMENTS_TABLES

DERIVATIVE INSTRUMENTS (TABLES)	12 Months Ended
	Dec. 31, 2013
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
LOCATION AND AMOUNTS OF DERIVATIVE FAIR VALUES ON THE CONSOLIDATED BALANCE SHEET [Table Text Block]	'
			At December 31, 2013												At December 31, 2012
			Derivative				Asset				Liability				Derivative				Asset		Liability
			Notional				Derivative				Derivative				Notional				Derivative		Derivative
			Amount				Fair				Fair				Amount				Fair		Fair
							Value(1)				Value(1)								Value(1)		Value(1)
		Derivatives not designated as hedging instruments
		Relating to investment portfolio:
		Foreign exchange forward contracts	$	254,023			1,214				1,032				$	287,819			1,067		2,733
		Interest rate swaps	281,250				873				—				—				—		—
		Relating to underwriting portfolio:
		Foreign exchange forward contracts	390,663				4,737				120				476,191				4,771		1,004
		Weather-related contracts	24,451				984				815				—				—		—
		Total derivatives					$	7,808			$	1,967							$	5,838	$	3,737
	-1	Asset and liability derivatives are classified within other assets and other liabilities on the Consolidated Balance Sheets.
RECONCILIATION OF GROSS DERIVATIVE ASSETS AND LIABILITIES TO NET AMOUNTS PRESENTED IN BALANCE SHEETS [Table Text Block]	'
			December 31, 2013										December 31, 2012
			Gross Amounts			Gross Amounts Offset			Net				Gross Amounts			Gross Amounts Offset			Net
									Amounts(1)										Amounts(1)
		Derivative assets	$	9,796		$	(1,988	)	$	7,808			$	6,476		$	(639	)	$	5,838
		Derivative liabilities	3,955			(1,988		)	1,967				4,376			(639		)	3,737
	-1	Net asset and liability derivatives are classified within other assets and other liabilities on the Consolidated Balance Sheets.
NET EARNINGS IMPACT OF FAIR VALUE HEDGES AND TOTAL UNREALIZED AND REALIZED GAINS (LOSSES) ON DERIVATIVES NOT DESIGNATED AS HEDGES RECORDED IN EARNINGS [Table Text Block]	'
		Year ended December 31,	2013				2012				2011
		Foreign exchange forward contracts	$	—			$	10,853			$	11,682
		Hedged investment portfolio	—				(3,099		)		(16,085		)
		Hedge ineffectiveness recognized in earnings	$	—			$	7,754			$	(4,403	)
			Location of Gain (Loss) Recognized	Amount of Gain (Loss) Recognized  in
			in Income on Derivative	Income on Derivative
				2013				2012				2011
		Derivatives not designated as hedging instruments
		Relating to investment portfolio:
		Foreign exchange forward contracts	Net realized investment gains	$	10,843			$	(9,170	)		$	4,431
		Interest rate swaps	Net realized investment gains	(3,112		)		—				—
		Relating to underwriting portfolio:
		Foreign exchange forward contracts	Foreign exchange gains (losses)	1,690				26,612				33,893
		Currency collar options	Foreign exchange gains (losses)	—				—				267
		Weather-related contracts	Other insurance related income	1,987				—				—
		Total		$	11,408			$	17,442			$	38,591

RESERVE_FOR_LOSSES_AND_LOSS_EX1

RESERVE FOR LOSSES AND LOSS EXPENSES (TABLES)	12 Months Ended
	Dec. 31, 2013
Insurance Loss Reserves [Abstract]	'
COMPONENTS OF RESERVE FOR LOSSES AND LOSS EXPENSES [Table Text Block]	'
		As of December 31,	2013			2012
		Reserve for reported losses and loss expenses	$	3,499,817		$	3,272,682
		Reserve for losses incurred but not reported	6,082,323			5,786,049
		Reserve for losses and loss expenses	$	9,582,140		$	9,058,731
RECONCILIATION OF BEGINNING AND ENDING GROSS RESERVE FOR LOSSES AND LOSS EXPENSES AND NET RESERVE FOR UNPAID LOSSES AND LOSS EXPENSES [Table Text Block]	'
		Year ended December 31,	2013			2012			2011
		Gross reserve for losses and loss expenses, beginning of period	$	9,058,731		$	8,425,045		$	7,032,375
		Less reinsurance recoverable on unpaid losses, beginning of period	(1,825,617		)	(1,736,823		)	(1,540,633		)
		Net reserve for unpaid losses and loss expenses, beginning of period	7,233,114			6,688,222			5,491,742
		Net incurred losses and loss expenses related to:
		Current year	2,353,631			2,340,868			2,932,513
		Prior years	(219,436		)	(244,840		)	(257,461		)
			2,134,195			2,096,028			2,675,052
		Net paid losses and loss expenses related to:
		Current year	(318,006		)	(322,836		)	(509,075		)
		Prior years	(1,373,459		)	(1,299,384		)	(953,035		)
			(1,691,465		)	(1,622,220		)	(1,462,110		)
		Foreign exchange and other	6,184			71,084			(16,462		)
		Net reserve for unpaid losses and loss expenses, end of period	7,682,028			7,233,114			6,688,222
		Reinsurance recoverable on unpaid losses, end of period	1,900,112			1,825,617			1,736,823
		Gross reserve for losses and loss expenses, end of period	$	9,582,140		$	9,058,731		$	8,425,045
NET PRIOR YEAR RESERVE DEVELOPMENT BY SEGMENT [Table Text Block]	'
			Insurance			Reinsurance			Total
		Year ended December 31, 2013	$	50,355		$	169,081		$	219,436
		Year ended December 31, 2012	122,209			122,631			244,840
		Year ended December 31, 2011	103,014			154,447			257,461

REINSURANCE_TABLES

REINSURANCE (TABLES)	12 Months Ended
	Dec. 31, 2013
Reinsurance Disclosures [Abstract]	'
BREAKDOWN OF GROSS AND NET PREMIUMS WRITTEN AND EARNED [Table Text Block]	'
		Year ended December 31,	2013						2012						2011
			Premiums			Premiums			Premiums			Premiums			Premiums			Premiums
			written			earned			written			earned			written			earned
		Gross	$	4,697,041		$	4,459,269		$	4,139,643		$	4,141,037		$	4,096,153		$	3,973,956
		Ceded	(768,841		)	(752,204		)	(802,187		)	(725,574		)	(676,719		)	(658,995		)
		Net	$	3,928,200		$	3,707,065		$	3,337,456		$	3,415,463		$	3,419,434		$	3,314,961

COMMITMENTS_AND_CONTINGENCIES_

COMMITMENTS AND CONTINGENCIES (TABLES)	12 Months Ended
	Dec. 31, 2013
Commitments and Contingencies Disclosure [Abstract]	'
FUTURE MINIMUM LEASE PAYMENTS UNDER OPERATING LEASES [Table Text Block]	'
		Year ended December 31,
		2014	$	31,207
		2015	27,378
		2016	23,838
		2017	20,881
		2018	17,955
		Later years	53,049
		Total future minimum lease payments	$	174,308

EARNINGS_PER_COMMON_SHARE_TABL

EARNINGS PER COMMON SHARE (TABLES)	12 Months Ended
	Dec. 31, 2013
Earnings Per Share [Abstract]	'
BASIC AND DILUTED EARNINGS PER COMMON SHARE [Table Text Block]	'
		At and year ended December 31,	2013		2012		2011
		Basic earnings per common share
		Net income	$	727,465	$	547,241	$	46,305
		Less: preferred share dividends	40,474		38,228		36,875
		Less: loss on repurchase of preferred shares	3,081		14,009		—
		Net income available to common shareholders	683,910		495,004		9,430
		Weighted average common shares outstanding - basic	113,636		122,148		122,499
		Basic earnings per common share	$	6.02	$	4.05	$	0.08
		Diluted earnings per common share
		Net income available to common shareholders	$	683,910	$	495,004	$	9,430
		Weighted average common shares outstanding - basic	113,636		122,148		122,499
		Warrants	—		—		4,292
		Stock compensation plans	1,692		1,506		1,331
		Weighted average common shares outstanding - diluted	115,328		123,654		128,122
		Diluted earnings per common share	$	5.93	$	4	$	0.07
		Anti-dilutive shares excluded from the dilutive computation	250		614		1,134

SHAREHOLDERS_EQUITY_TABLES

SHAREHOLDERS' EQUITY (TABLES)	12 Months Ended
	Dec. 31, 2013
Stockholders' Equity Note [Abstract]	'
COMMON SHARES ISSUED AND OUTSTANDING [Table Text Block]	'
		Year ended December 31,	2013		2012			2011
		Shares issued, balance at beginning of period	171,867		170,159			154,912
		Shares issued	2,267		1,708			15,247
		Total shares issued at end of period	174,134		171,867			170,159
		Treasury shares, balance at beginning of period	(53,947	)	(44,571	)		(42,519	)
		Shares repurchased	(10,830	)	(9,376	)		(2,052	)
		Shares reissued from treasury	128		—			—
		Total treasury shares at end of period	(64,649	)	(53,947	)		(44,571	)
		Total shares outstanding	109,485		117,920			125,588
SHARE REPURCHASES [Table Text Block]	'
		Year ended December 31,	2013			2012				2011
		In the open market:
		Total shares	7,362			6,057				1,609
		Total cost	$	337,083		$	203,704			$	49,974
		Average price per share(2)	$	45.79		$	33.63			$	31.07
		From employees:(1)
		Total shares	468			319				443
		Total cost	$	19,080		$	10,483			$	15,911
		Average price per share(2)	$	40.75		$	32.85			$	35.92
		From founding shareholder:(3)
		Total shares	3,000			3,000				—
		Total cost	$	116,100		$	103,500			$	—
		Average price per share(2)	$	38.7		$	34.5			$	—
		Total
		Total shares	10,830			9,376				2,052
		Total cost	$	472,263		$	317,687			$	65,885
		Average price per share(2)	$	43.61		$	33.88			$	32.11
	-1	To satisfy withholding tax liabilities upon vesting of restricted stock, restricted stock units, and exercise of stock options. Share repurchases from employees are excluded from the authorized share repurchase plans noted above.
	-2	Calculated using whole figures.
	-3	We privately negotiated with Trident II, L.P. and affiliated entities to repurchase 3,000,000 (2012: 3,000,000; 2011: none) of our common shares.

SHAREBASED_COMPENSATION_TABLES

SHARE-BASED COMPENSATION (TABLES)	12 Months Ended
	Dec. 31, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
RECONCILIATION OF BEGINNING AND ENDING BALANCE OF NONVESTED RESTRICTED STOCK (INCLUDING RSUS) TO BE SETTLED IN SHARES [Table Text Block]	'
			Performance-based Stock Awards				Service-based Stock Awards
			Number of		Weighted Average		Number of			Weighted Average
			Restricted		Grant Date		Restricted			Grant Date
			Stock		Fair Value		Stock			Fair Value
		Nonvested restricted stock - beginning of year	250		$	34.42	4,429			$	32.48
		Granted	33		45.89		975			39.31
		Vested	—		—		(1,754	)		32.03
		Forfeited	—		—		(220	)		34.17
		Nonvested restricted stock - end of year	283		$	35.74	3,430			$	34.72
	(1) Fair value is based on the closing price of our common shares on the New York Stock Exchange on the day of the grant.
SUMMARY OF STOCK OPTIONS OUTSTANDING AND EXERCISABLE AND RELATED ACTIVITY FOR PERIOD [Table Text Block]	'
			Number		Weighted		Weighted		Aggregate
			of Stock		Average		Average		Intrinsic
			Options		Exercise		Remaining		Value(1)
					Price		Contractual
							Term
		Outstanding and exercisable - beginning of year	919		$	28.74
		Granted	—		—
		Exercised	(706	)	28.96
		Expired	—		—
		Outstanding and exercisable - end of year	213		$	27.98	1		$	4,180
	-1	The aggregate intrinsic value in the table above represents the total pre-tax intrinsic value (the difference between our closing stock price at December 31, 2013 and the exercisable price, multiplied by the number of in-the-money-options) that would have been received by the stock option holder had all stock option holders exercised their stock options on December 31, 2013.

INCOME_TAXES_TABLES

INCOME TAXES (TABLES)	12 Months Ended
	Dec. 31, 2013
INCOME TAXES [Abstract]	'
SCHEDULE OF INCOME TAX EXPENSE AND NET TAX ASSETS [Table Text Block]	'
		Year ended December 31,	2013			2012			2011
		Current income tax expense (benefit)
		United States	$	12,466		$	4,931		$	5,064
		Europe	9,039			8,566			9,598
		Other	—			(174		)	188
		Deferred income tax expense (benefit)
		United States	(13,976		)	(10,749		)	1,379
		Europe	(526		)	713			(996		)
		Other	(1		)	—			—
		Total income tax expense	$	7,002		$	3,287		$	15,233
		Net current tax receivables	$	5,689		$	1,164		$	1,318
		Net deferred tax assets	80,258			52,794			60,836
		Net tax assets	$	85,947		$	53,958		$	62,154
SCHEDULE OF DEFERRED TAX ASSETS AND LIABILITIES [Table Text Block]	'
		At December 31,	2013			2012
		Deferred tax assets:
		Discounting of loss reserves	$	59,023		$	61,534
		Unearned premiums	39,146			32,355
		Operating loss carryforwards	20,316			20,685
		Accruals not currently deductible	39,018			25,638
		Other investment adjustments and impairments	7,859			8,790
		Tax credits	11,886			7,945
		Depreciation	2,410			3,858
		Other deferred tax assets	2,906			2,185
		Deferred tax assets before valuation allowance	182,564			162,990
		Valuation allowance	(25,542		)	(24,574		)
		Deferred tax assets net of valuation allowance	157,022			138,416
		Deferred tax liabilities:
		Deferred acquisition costs	(37,226		)	(27,211		)
		Net unrealized gains on investments	(23,200		)	(44,137		)
		Amortization of intangible assets and goodwill	(10,059		)	(8,258		)
		Accrued market discounts	(1,151		)	(1,323		)
		Equalization reserves	(2,080		)	(1,957		)
		Other deferred tax liabilities	(3,048		)	(2,736		)
		Deferred tax liabilities	(76,764		)	(85,622		)
		Net deferred tax assets	$	80,258		$	52,794
VALUATION ALLOWANCE ROLL FORWARD [Table Text Block]	'
		At December 31,	2013			2012
		Income tax expense:
		Valuation allowance - beginning of year	$	33,933		$	30,623
		Operating loss carryforwards	(794		)	635
		Foreign tax credit	1,762			2,675
		Change in investment-related items	(7,831		)	—
		Valuation allowance - end of year	27,070			33,933
		Accumulated other comprehensive income:
		Valuation allowance - beginning of year	(9,359		)	(9,359		)
		Change in investment-related items	7,831			—
		Valuation allowance - end of year	(1,528		)	(9,359		)
		Total valuation allowance - end of year	$	25,542		$	24,574
EFFECTIVE TAX RATE RECONCILIATION [Table Text Block]	'
		Year ended December 31,	2013			2012			2011
		Income before income taxes
		Bermuda (domestic)	$	625,490		$	485,613		$	10,911
		Foreign	108,977			64,915			50,627
		Total income before income taxes	$	734,467		$	550,528		$	61,538
		Reconciliation of effective tax rate (% of income before income taxes)
		Expected tax rate	0		%	0		%	0		%
		Foreign taxes at local expected rates:
		United States	2.1		%	0.4		%	33.2		%
		Europe	1		%	1.4		%	10.7		%
		Other	0.3		%	—		%	3.3		%
		Valuation allowance	(0.7		)%	0.6		%	(15.5		)%
		Net tax exempt income	(1.3		)%	(1.5		)%	(11.2		)%
		Other	(0.4		)%	(0.3		)%	4.3		%
		Actual tax rate	1		%	0.6		%	24.8		%

OTHER_COMPREHENSIVE_INCOME_LOS1

OTHER COMPREHENSIVE INCOME (LOSS) (TABLES)	12 Months Ended
	Dec. 31, 2013
Equity [Abstract]	'
TAX EFFECTS ALLOCATED TO EACH COMPONENT OF OTHER COMPREHENSIVE INCOME (LOSS) [Table Text Block]	'
			Before Tax Amount				Tax (Expense) Benefit				Net of Tax Amount
		Year ended December 31, 2013
		Available for sale investments:
		Unrealized investment losses arising during the period	$	(169,614	)		$	7,782			$	(161,832	)
		Adjustment for reclassification of net realized investment gains and OTTI losses recognized in net income	(67,156		)		5,605				(61,551		)
		Unrealized investment losses arising during the period, net of reclassification adjustment	(236,770		)		13,387				(223,383		)
		Non-credit portion of OTTI losses	—				—				—
		Foreign currency translation adjustment	(21,414		)		—				(21,414		)
		Net change in benefit plan assets and obligations recognized in equity and reclassification adjustment	—				—				—
		Total other comprehensive loss	$	(258,184	)		$	13,387			$	(244,797	)
		Year ended December 31, 2012
		Available for sale investments:
		Unrealized investment gains arising during the period	$	378,040			$	(29,530	)		$	348,510
		Adjustment for reclassification of net realized investment gains and OTTI losses recognized in net income	(127,828		)		11,550				(116,278		)
		Unrealized investment gains arising during the period, net of reclassification adjustment	250,212				(17,980		)		232,232
		Non-credit portion of OTTI losses	—				—				—
		Foreign currency translation adjustment	510				—				510
		Net change in benefit plan assets and obligations recognized in equity and reclassification adjustment	1,718				—				1,718
		Total other comprehensive income	$	252,440			$	(17,980	)		$	234,460
		Year ended December 31, 2011
		Available for sale investments:
		Unrealized investment gains arising during the period	87,384				(13,087		)		74,297
		Adjustment for reclassification of net realized investment gains and OTTI losses recognized in net income	(121,248		)		1,700				(119,548		)
		Unrealized investment losses arising during the period, net of reclassification adjustment	(33,864		)		(11,387		)		(45,251		)
		Non-credit portion of OTTI losses	(585		)		130				(455		)
		Foreign currency translation adjustment	(3,045		)		—				(3,045		)
		Net change in benefit plan assets and obligations recognized in equity and reclassification adjustment	92				—				92
		Total other comprehensive loss	(37,402		)		(11,257		)		(48,659		)
RECLASSIFICATIONS OUT OF AOCI INTO NET INCOME AVAILABLE TO COMMON SHAREHOLDERS [Table Text Block]	'
				Amount Reclassified from AOCI(1)
		Details About AOCI Components	Consolidated Statement of Operations Line Item That Includes Reclassification	Year ended December 31,
				2013				2012				2011
		Unrealized appreciation on available for sale investments
			Other realized investment gains	$	76,518			$	152,062			$	137,694
			OTTI losses	(9,362		)		(24,234		)		(16,446		)
			Total before tax	67,156				127,828				121,248
			Tax expense	(5,605		)		(11,550		)		(1,700		)
			Net of tax	$	61,551			$	116,278			$	119,548
		Supplemental Executive Retirement Plans (SERPs)
		Net change in benefit plan assets and obligations	General and administrative expenses	$	—			$	(1,718	)		$	(92	)
			Tax benefit	—				—				—
			Net of tax	$	—			$	(1,718	)		$	(92	)
	-1	Amounts in parentheses are debits to net income available to common shareholders

STATUTORY_FINANCIAL_INFORMATIO1

STATUTORY FINANCIAL INFORMATION (TABLES)	12 Months Ended
	Dec. 31, 2013
STATUTORY FINANCIAL INFORMATION [Abstract]	'
STATUTORY CAPITAL AND SURPLUS BY JURISDICTION [Table Text Block]	'
			Bermuda				Ireland				United States
		At December 31,	2013		2012		2013		2012		2013		2012
		Required statutory capital and surplus	$	1,996,794	$	2,048,329	$	315,258	$	279,078	$	385,651	$	358,674
		Actual statutory capital and surplus	$	3,839,840	$	4,091,437	$	906,932	$	904,237	$	1,348,861	$	1,295,679

UNAUDITED_CONDENSED_QUARTERLY_1

UNAUDITED CONDENSED QUARTERLY FINANCIAL DATA (TABLES)	12 Months Ended
	Dec. 31, 2013
Quarterly Financial Information Disclosure [Abstract]	'
UNAUDITED SUMMARY OF QUARTERLY FINANCIAL RESULTS [Table Text Block]	'
		Quarters ended	31-Mar		30-Jun		30-Sep			31-Dec
		2013
		Net premiums earned	$	874,039	$	945,873	$	945,242		$	941,911
		Net investment income	108,908		83,112		103,429			113,863
		Net realized investment gains (losses)	44,478		16,235		(4,708		)	19,558
		Underwriting income	170,799		9,921		153,088			94,159
		Net income available to common shareholders	302,816		72,447		137,121			171,524
		Earnings per common share - basic	$	2.59	$	0.63	$	1.23		$	1.55
		Earnings per common share - diluted	$	2.55	$	0.62	$	1.21		$	1.52
		2012
		Net premiums earned	$	846,362	$	850,603	$	862,447		$	856,049
		Net investment income	116,023		74,449		103,638			86,847
		Net realized investment gains	14,491		30,405		50,803			31,771
		Underwriting income (loss)	62,689		119,739		154,999			(74,291		)
		Net income (loss) available to common shareholders	121,997		168,152		223,407			(18,551		)
		Earnings (loss) per common share - basic	$	0.97	$	1.36	$	1.84		$	(0.16	)
		Earnings (loss) per common share - diluted	$	0.96	$	1.35	$	1.82		$	(0.16	)

SEGMENT_INFORMATION_DETAILS

SEGMENT INFORMATION (DETAILS) (USD $)	3 Months Ended								12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
									reportable_segment
Segment Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Number of reportable segments	'	'	'	'	'	'	'	'	2	'	'
Gross premiums written	'	'	'	'	'	'	'	'	$4,697,041	$4,139,643	$4,096,153
Net premiums written	'	'	'	'	'	'	'	'	3,928,200	3,337,456	3,419,434
Net premiums earned	941,911	945,242	945,873	874,039	856,049	862,447	850,603	846,362	3,707,065	3,415,463	3,314,961
Other insurance related income	'	'	'	'	'	'	'	'	4,424	2,676	2,396
Net losses and loss expenses	'	'	'	'	'	'	'	'	-2,134,195	-2,096,028	-2,675,052
Acquisition costs	'	'	'	'	'	'	'	'	-664,191	-627,653	-587,469
General and administrative expenses	'	'	'	'	'	'	'	'	-575,390	-560,981	-459,151
Underwriting income (loss)	94,159	153,088	9,921	170,799	-74,291	154,999	119,739	62,689	'	'	'
Net investment income	113,863	103,429	83,112	108,908	86,847	103,638	74,449	116,023	409,312	380,957	362,430
Net realized investment gains	19,558	-4,708	16,235	44,478	31,771	50,803	30,405	14,491	75,564	127,469	121,439
Foreign exchange (losses) gains	'	'	'	'	'	'	'	'	-26,143	-29,512	44,582
Interest expense and financing costs	'	'	'	'	'	'	'	'	-61,979	-61,863	-62,598
Income before income taxes	'	'	'	'	'	'	'	'	734,467	550,528	61,538
Net loss and loss expense ratio	'	'	'	'	'	'	'	'	57.60%	61.40%	80.70%
Acquisition cost ratio	'	'	'	'	'	'	'	'	17.90%	18.40%	17.70%
General and administrative expense ratio	'	'	'	'	'	'	'	'	15.50%	16.40%	13.90%
Combined ratio	'	'	'	'	'	'	'	'	91.00%	96.20%	112.30%
Goodwill and intangible assets	89,528	'	'	'	97,493	'	'	'	89,528	97,493	99,590
Insurance [Member]	'	'	'	'	'	'	'	'	'	'	'
Segment Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net premiums earned	'	'	'	'	'	'	'	'	1,722,762	1,558,058	1,429,687
Reinsurance [Member]	'	'	'	'	'	'	'	'	'	'	'
Segment Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net premiums earned	'	'	'	'	'	'	'	'	1,984,303	1,857,405	1,885,274
Operating Segments [Member]	'	'	'	'	'	'	'	'	'	'	'
Segment Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Gross premiums written	'	'	'	'	'	'	'	'	4,697,041	4,139,643	4,096,153
Net premiums written	'	'	'	'	'	'	'	'	3,928,200	3,337,456	3,419,434
Net premiums earned	'	'	'	'	'	'	'	'	3,707,065	3,415,463	3,314,961
Other insurance related income	'	'	'	'	'	'	'	'	4,424	2,676	2,396
Net losses and loss expenses	'	'	'	'	'	'	'	'	-2,134,195	-2,096,028	-2,675,052
Acquisition costs	'	'	'	'	'	'	'	'	-664,191	-627,653	-587,469
General and administrative expenses	'	'	'	'	'	'	'	'	-485,134	-431,321	-382,062
Underwriting income (loss)	'	'	'	'	'	'	'	'	427,969	263,137	-327,226
Operating Segments [Member] | Insurance [Member]	'	'	'	'	'	'	'	'	'	'	'
Segment Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Gross premiums written	'	'	'	'	'	'	'	'	2,559,138	2,309,481	2,121,829
Net premiums written	'	'	'	'	'	'	'	'	1,813,538	1,522,245	1,466,134
Net premiums earned	'	'	'	'	'	'	'	'	1,722,762	1,558,058	1,429,687
Other insurance related income	'	'	'	'	'	'	'	'	2,436	2,676	2,396
Net losses and loss expenses	'	'	'	'	'	'	'	'	-1,050,402	-953,564	-919,319
Acquisition costs	'	'	'	'	'	'	'	'	-242,363	-226,859	-199,583
General and administrative expenses	'	'	'	'	'	'	'	'	-347,684	-314,834	-278,147
Underwriting income (loss)	'	'	'	'	'	'	'	'	84,749	65,477	35,034
Net loss and loss expense ratio	'	'	'	'	'	'	'	'	61.00%	61.20%	64.30%
Acquisition cost ratio	'	'	'	'	'	'	'	'	14.10%	14.60%	14.00%
General and administrative expense ratio	'	'	'	'	'	'	'	'	20.10%	20.20%	19.40%
Combined ratio	'	'	'	'	'	'	'	'	95.20%	96.00%	97.70%
Goodwill and intangible assets	89,528	'	'	'	97,493	'	'	'	89,528	97,493	99,590
Operating Segments [Member] | Reinsurance [Member]	'	'	'	'	'	'	'	'	'	'	'
Segment Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Gross premiums written	'	'	'	'	'	'	'	'	2,137,903	1,830,162	1,974,324
Net premiums written	'	'	'	'	'	'	'	'	2,114,662	1,815,211	1,953,300
Net premiums earned	'	'	'	'	'	'	'	'	1,984,303	1,857,405	1,885,274
Other insurance related income	'	'	'	'	'	'	'	'	1,988	0	0
Net losses and loss expenses	'	'	'	'	'	'	'	'	-1,083,793	-1,142,464	-1,755,733
Acquisition costs	'	'	'	'	'	'	'	'	-421,828	-400,794	-387,886
General and administrative expenses	'	'	'	'	'	'	'	'	-137,450	-116,487	-103,915
Underwriting income (loss)	'	'	'	'	'	'	'	'	343,220	197,660	-362,260
Net loss and loss expense ratio	'	'	'	'	'	'	'	'	54.60%	61.50%	93.10%
Acquisition cost ratio	'	'	'	'	'	'	'	'	21.30%	21.60%	20.60%
General and administrative expense ratio	'	'	'	'	'	'	'	'	6.90%	6.30%	5.50%
Combined ratio	'	'	'	'	'	'	'	'	82.80%	89.40%	119.20%
Goodwill and intangible assets	0	'	'	'	0	'	'	'	0	0	0
Corporate [Member]	'	'	'	'	'	'	'	'	'	'	'
Segment Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
General and administrative expenses	'	'	'	'	'	'	'	'	-90,256	-129,660	-77,089
Significant Reconciling Items [Member]	'	'	'	'	'	'	'	'	'	'	'
Segment Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net investment income	'	'	'	'	'	'	'	'	409,312	380,957	362,430
Net realized investment gains	'	'	'	'	'	'	'	'	75,564	127,469	121,439
Foreign exchange (losses) gains	'	'	'	'	'	'	'	'	-26,143	-29,512	44,582
Interest expense and financing costs	'	'	'	'	'	'	'	'	($61,979)	($61,863)	($62,598)

SEGMENT_INFORMATION_DETAILS_2

SEGMENT INFORMATION (DETAILS 2) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Revenues From External Customers By Geographic Location Of Subsidiary [Line Items]	'	'	'
Gross premiums written	$4,697,041	$4,139,643	$4,096,153
Bermuda [Member]	'	'	'
Revenues From External Customers By Geographic Location Of Subsidiary [Line Items]	'	'	'
Gross premiums written	718,904	684,588	822,237
Europe [Member]	'	'	'
Revenues From External Customers By Geographic Location Of Subsidiary [Line Items]	'	'	'
Gross premiums written	1,699,748	1,561,701	1,493,692
United States [Member]	'	'	'
Revenues From External Customers By Geographic Location Of Subsidiary [Line Items]	'	'	'
Gross premiums written	$2,278,389	$1,893,354	$1,780,224

SEGMENT_INFORMATION_DETAILS_3

SEGMENT INFORMATION (DETAILS 3) (USD $)	3 Months Ended								12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Revenue from External Customer [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net premiums earned	$941,911	$945,242	$945,873	$874,039	$856,049	$862,447	$850,603	$846,362	$3,707,065	$3,415,463	$3,314,961
Insurance [Member]	'	'	'	'	'	'	'	'	'	'	'
Revenue from External Customer [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net premiums earned	'	'	'	'	'	'	'	'	1,722,762	1,558,058	1,429,687
Insurance [Member] | Property [Member]	'	'	'	'	'	'	'	'	'	'	'
Revenue from External Customer [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net premiums earned	'	'	'	'	'	'	'	'	462,364	408,943	385,291
Insurance [Member] | Marine [Member]	'	'	'	'	'	'	'	'	'	'	'
Revenue from External Customer [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net premiums earned	'	'	'	'	'	'	'	'	179,057	171,165	152,123
Insurance [Member] | Terrorism [Member]	'	'	'	'	'	'	'	'	'	'	'
Revenue from External Customer [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net premiums earned	'	'	'	'	'	'	'	'	39,298	38,605	35,213
Insurance [Member] | Aviation [Member]	'	'	'	'	'	'	'	'	'	'	'
Revenue from External Customer [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net premiums earned	'	'	'	'	'	'	'	'	48,489	60,363	70,681
Insurance [Member] | Credit and political risk [Member]	'	'	'	'	'	'	'	'	'	'	'
Revenue from External Customer [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net premiums earned	'	'	'	'	'	'	'	'	68,192	87,103	97,680
Insurance [Member] | Professional lines [Member]	'	'	'	'	'	'	'	'	'	'	'
Revenue from External Customer [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net premiums earned	'	'	'	'	'	'	'	'	586,200	563,500	536,238
Insurance [Member] | Liability [Member]	'	'	'	'	'	'	'	'	'	'	'
Revenue from External Customer [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net premiums earned	'	'	'	'	'	'	'	'	110,623	86,873	89,555
Insurance [Member] | Accident and health [Member]	'	'	'	'	'	'	'	'	'	'	'
Revenue from External Customer [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net premiums earned	'	'	'	'	'	'	'	'	228,539	141,506	62,906
Reinsurance [Member]	'	'	'	'	'	'	'	'	'	'	'
Revenue from External Customer [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net premiums earned	'	'	'	'	'	'	'	'	1,984,303	1,857,405	1,885,274
Reinsurance [Member] | Catastrophe [Member]	'	'	'	'	'	'	'	'	'	'	'
Revenue from External Customer [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net premiums earned	'	'	'	'	'	'	'	'	380,199	375,088	456,858
Reinsurance [Member] | Property [Member]	'	'	'	'	'	'	'	'	'	'	'
Revenue from External Customer [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net premiums earned	'	'	'	'	'	'	'	'	350,970	351,470	356,022
Reinsurance [Member] | Professional lines [Member]	'	'	'	'	'	'	'	'	'	'	'
Revenue from External Customer [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net premiums earned	'	'	'	'	'	'	'	'	304,754	297,726	281,025
Reinsurance [Member] | Credit and surety [Member]	'	'	'	'	'	'	'	'	'	'	'
Revenue from External Customer [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net premiums earned	'	'	'	'	'	'	'	'	279,943	277,185	263,912
Reinsurance [Member] | Motor [Member]	'	'	'	'	'	'	'	'	'	'	'
Revenue from External Customer [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net premiums earned	'	'	'	'	'	'	'	'	221,844	237,006	202,830
Reinsurance [Member] | Liability [Member]	'	'	'	'	'	'	'	'	'	'	'
Revenue from External Customer [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net premiums earned	'	'	'	'	'	'	'	'	234,736	220,874	230,872
Reinsurance [Member] | Agriculture [Member]	'	'	'	'	'	'	'	'	'	'	'
Revenue from External Customer [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net premiums earned	'	'	'	'	'	'	'	'	126,490	17,116	15,031
Reinsurance [Member] | Engineering [Member]	'	'	'	'	'	'	'	'	'	'	'
Revenue from External Customer [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net premiums earned	'	'	'	'	'	'	'	'	66,243	68,402	65,727
Reinsurance [Member] | Other [Member]	'	'	'	'	'	'	'	'	'	'	'
Revenue from External Customer [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net premiums earned	'	'	'	'	'	'	'	'	$19,124	$12,538	$12,997

GOODWILL_AND_INTANGIBLE_ASSETS2

GOODWILL AND INTANGIBLE ASSETS (DETAILS) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Goodwill [Roll Forward]	'	'
Goodwill net balance, opening	$49,635	$49,350
Foreign currency translation adjustment, goodwill	-3,213	285
Goodwill net balance, closing	46,422	49,635
Goodwill, gross	42,237	'
Accumulated foreign currency translation adjustment, goodwill	4,185	'
Goodwill, net	46,422	49,635
Intangible Assets with an Indefinite Life [Roll Forward]	'	'
Intangible assets with an indefinite life net balance, opening	26,036	26,036
Foreign currency translation adjustment, intangible assets with an indefinite life	0	0
Intangible assets with an indefinite life net balance, closing	26,036	26,036
Intangible assets with an indefinite life, gross	26,036	'
Accumulated foreign currency translation adjustment, intangible assets with an indefinite life	0	'
Intangible assets with an indefinite life, net	26,036	26,036
Intangible Assets with a Finite Life [Roll Forward]	'	'
Intangible assets with a finite life net balance, opening	21,822	24,204
Amortization, intangible assets with a finite life	-2,233	-2,618
Foreign currency translation adjustment, intangible assets with a finite life	-2,519	236
Intangible assets with a finite life net balance, closing	17,070	21,822
Intangible assets with a finite life, gross	35,596	'
Accumulated amortization, intangible assets with a finite life	-23,601	'
Accumulated foreign currency translation adjustment, intangible assets with a finite life	5,075	'
Intangible assets with a finite life, net	17,070	21,822
Goodwill and Intangible Assets [Roll Forward]	'	'
Goodwill and intangible assets net balance, opening	97,493	99,590
Amortization, intangible assets with a finite life	-2,233	-2,618
Foreign currency translation adjustment, goodwill and intangible assets	-5,732	521
Goodwill and intangible assets net balance, closing	89,528	97,493
Goodwill and intangible assets, gross	103,869	'
Accumulated amortization, intangible assets with a finite life	-23,601	'
Accumulated foreign currency translation, goodwill and intangible assets	9,260	'
Goodwill and intangible assets, net	$89,528	$97,493

GOODWILL_AND_INTANGIBLE_ASSETS3

GOODWILL AND INTANGIBLE ASSETS (DETAILS 2) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013
Finite-Lived Intangible Assets [Line Items]	'
Intangible assets with a finite life - future amortization in year one	2
Intangible assets with a finite life - future amortization in year two	2
Intangible assets with a finite life - future amortization in year three	2
Intangible assets with a finite life - future amortization in year four	2
Intangible assets with a finite life - future amortization in year five	2
Minimum [Member]	'
Finite-Lived Intangible Assets [Line Items]	'
Intangible assets with a finite life - remaining useful life	'6 years
Maximum [Member]	'
Finite-Lived Intangible Assets [Line Items]	'
Intangible assets with a finite life - remaining useful life	'25 years

INVESTMENTS_DETAILS

INVESTMENTS (DETAILS) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Schedule Of Available For Sale Securities [Line Items]	'	'
Amortized Cost	$11,987,146	$11,605,672
Gross Unrealized Gains (fixed maturities)	179,218	340,862
Gross Unrealized Losses (fixed maturities)	-180,037	-18,485
Fair Value (fixed maturities)	11,986,327	11,928,049
Non-credit OTTI in AOCI	-868	-884
Cost	566,219	608,306
Gross Unrealized Gains (equities)	141,951	65,640
Gross Unrealized Losses (equities)	-6,183	-7,398
Fair Value (equities)	701,987	666,548
US Government and Agency [Member]	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'
Amortized Cost	1,421,245	1,413,520
Gross Unrealized Gains (fixed maturities)	1,405	9,484
Gross Unrealized Losses (fixed maturities)	-33,952	-119
Fair Value (fixed maturities)	1,388,698	1,422,885
Non-credit OTTI in AOCI	0	0
Non-US Government [Member]	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'
Amortized Cost	1,208,384	1,076,501
Gross Unrealized Gains (fixed maturities)	17,990	30,276
Gross Unrealized Losses (fixed maturities)	-49,992	-2,201
Fair Value (fixed maturities)	1,176,382	1,104,576
Non-credit OTTI in AOCI	0	0
Corporate Debt [Member]	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'
Amortized Cost	3,533,585	3,746,616
Gross Unrealized Gains (fixed maturities)	84,881	135,658
Gross Unrealized Losses (fixed maturities)	-10,228	-5,892
Fair Value (fixed maturities)	3,608,238	3,876,382
Non-credit OTTI in AOCI	0	0
Agency RMBS [Member]	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'
Amortized Cost	2,485,139	2,594,180
Gross Unrealized Gains (fixed maturities)	21,979	67,398
Gross Unrealized Losses (fixed maturities)	-58,291	-1,670
Fair Value (fixed maturities)	2,448,827	2,659,908
Non-credit OTTI in AOCI	0	0
CMBS [Member]	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'
Amortized Cost	790,095	814,211
Gross Unrealized Gains (fixed maturities)	11,285	25,999
Gross Unrealized Losses (fixed maturities)	-3,966	-126
Fair Value (fixed maturities)	797,414	840,084
Non-credit OTTI in AOCI	0	0
Non-Agency RMBS [Member]	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'
Amortized Cost	65,590	93,266
Gross Unrealized Gains (fixed maturities)	2,375	2,503
Gross Unrealized Losses (fixed maturities)	-398	-570
Fair Value (fixed maturities)	67,567	95,199
Non-credit OTTI in AOCI	-868	-884
ABS [Member]	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'
Amortized Cost	955,274	639,614
Gross Unrealized Gains (fixed maturities)	6,871	10,774
Gross Unrealized Losses (fixed maturities)	-8,694	-7,182
Fair Value (fixed maturities)	953,451	643,206
Non-credit OTTI in AOCI	0	0
Municipals [Member]	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'
Amortized Cost	1,527,834	1,227,764
Gross Unrealized Gains (fixed maturities)	32,432	58,770
Gross Unrealized Losses (fixed maturities)	-14,516	-725
Fair Value (fixed maturities)	1,545,750	1,285,809
Non-credit OTTI in AOCI	0	0
Common Stock [Member]	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'
Cost	345,759	398,975
Gross Unrealized Gains (equities)	98,742	51,821
Gross Unrealized Losses (equities)	-6,183	-7,398
Fair Value (equities)	438,318	443,398
Exchange-Traded Funds [Member]	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'
Cost	106,762	109,434
Gross Unrealized Gains (equities)	32,085	9,727
Gross Unrealized Losses (equities)	0	0
Fair Value (equities)	138,847	119,161
Non-U.S. Bond Mutual Funds [Member]	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'
Cost	113,698	99,897
Gross Unrealized Gains (equities)	11,124	4,092
Gross Unrealized Losses (equities)	0	0
Fair Value (equities)	$124,822	$103,989

INVESTMENTS_DETAILS_2

INVESTMENTS (DETAILS 2) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Schedule Of Available For Sale Securities [Line Items]	'	'
Due in one year or less (amortized cost)	$710,079	$651,111
Due after one year through five years (amortized cost)	5,030,728	4,880,039
Due after five years through ten years (amortized cost)	1,852,877	1,847,295
Due after ten years (amortized cost)	97,364	85,956
Total fixed maturities with a single maturity date (amortized cost)	7,691,048	7,464,401
Total (amortized cost)	11,987,146	11,605,672
Due in one year or less (fair value)	717,052	657,045
Due after one year through five years (fair value)	5,116,060	4,989,151
Due after five years through ten years (fair value)	1,791,835	1,951,569
Due after ten years (fair value)	94,121	91,887
Total fixed maturities with a single maturity date (fair value)	7,719,068	7,689,652
Fair Value (fixed maturities)	11,986,327	11,928,049
Due in one year or less (% of total fair value)	5.90%	5.50%
Due after one year through five years (% of total fair value)	42.70%	41.80%
Due after five years through ten years (% of total fair value)	14.90%	16.40%
Due after ten years (% of total fair value)	0.80%	0.80%
Fixed maturities with single maturity date (% of total fair value)	64.30%	64.50%
Total	100.00%	100.00%
Agency RMBS [Member]	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'
Fixed maturities without a single maturity date (amortized cost)	2,485,139	2,594,180
Total (amortized cost)	2,485,139	2,594,180
Fixed maturities without a single maturity date (fair value)	2,448,827	2,659,908
Fair Value (fixed maturities)	2,448,827	2,659,908
Fixed maturities without a single maturity date (% of total fair value)	20.40%	22.30%
CMBS [Member]	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'
Fixed maturities without a single maturity date (amortized cost)	790,095	814,211
Total (amortized cost)	790,095	814,211
Fixed maturities without a single maturity date (fair value)	797,414	840,084
Fair Value (fixed maturities)	797,414	840,084
Fixed maturities without a single maturity date (% of total fair value)	6.70%	7.00%
Non-Agency RMBS [Member]	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'
Fixed maturities without a single maturity date (amortized cost)	65,590	93,266
Total (amortized cost)	65,590	93,266
Fixed maturities without a single maturity date (fair value)	67,567	95,199
Fair Value (fixed maturities)	67,567	95,199
Fixed maturities without a single maturity date (% of total fair value)	0.60%	0.80%
ABS [Member]	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'
Fixed maturities without a single maturity date (amortized cost)	955,274	639,614
Total (amortized cost)	955,274	639,614
Fixed maturities without a single maturity date (fair value)	953,451	643,206
Fair Value (fixed maturities)	$953,451	$643,206
Fixed maturities without a single maturity date (% of total fair value)	8.00%	5.40%

INVESTMENTS_DETAILS_3

INVESTMENTS (DETAILS 3) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified	security	security
Fixed Maturities [Member]	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'
Fair Value - 12 months or greater	$271,520	$268,311
Unrealized Losses - 12 months or greater	-13,466	-12,405
Fair Value - Less than 12 months	4,889,507	1,432,707
Unrealized Losses - Less than 12 months	-166,571	-6,080
Total Fair Value of Securities in Unrealized Loss Position	5,161,027	1,701,018
Total Unrealized Losses	-180,037	-18,485
Number of Available For Sale Securities In Unrealized Loss Positions	1,127	478
Number of Available For Sale Securities in Unrealized Loss Positions for 12 Months or Greater	99	146
Fixed Maturities [Member] | Below Investment Grade or Not Rated [Member]	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'
Total Unrealized Losses	-2,000	-3,000
US Government and Agency [Member]	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'
Fair Value - 12 months or greater	0	0
Unrealized Losses - 12 months or greater	0	0
Fair Value - Less than 12 months	982,307	119,730
Unrealized Losses - Less than 12 months	-33,952	-119
Total Fair Value of Securities in Unrealized Loss Position	982,307	119,730
Total Unrealized Losses	-33,952	-119
Non-US Government [Member]	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'
Fair Value - 12 months or greater	35,577	44,568
Unrealized Losses - 12 months or greater	-3,430	-1,453
Fair Value - Less than 12 months	420,622	153,134
Unrealized Losses - Less than 12 months	-46,562	-748
Total Fair Value of Securities in Unrealized Loss Position	456,199	197,702
Total Unrealized Losses	-49,992	-2,201
Corporate Debt [Member]	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'
Fair Value - 12 months or greater	27,696	95,511
Unrealized Losses - 12 months or greater	-802	-2,947
Fair Value - Less than 12 months	606,592	451,651
Unrealized Losses - Less than 12 months	-9,426	-2,945
Total Fair Value of Securities in Unrealized Loss Position	634,288	547,162
Total Unrealized Losses	-10,228	-5,892
Agency RMBS [Member]	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'
Fair Value - 12 months or greater	144,468	9,557
Unrealized Losses - 12 months or greater	-5,247	-148
Fair Value - Less than 12 months	1,478,527	521,400
Unrealized Losses - Less than 12 months	-53,044	-1,522
Total Fair Value of Securities in Unrealized Loss Position	1,622,995	530,957
Total Unrealized Losses	-58,291	-1,670
CMBS [Member]	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'
Fair Value - 12 months or greater	13,319	1,749
Unrealized Losses - 12 months or greater	-116	-16
Fair Value - Less than 12 months	298,863	69,615
Unrealized Losses - Less than 12 months	-3,850	-110
Total Fair Value of Securities in Unrealized Loss Position	312,182	71,364
Total Unrealized Losses	-3,966	-126
Non-Agency RMBS [Member]	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'
Fair Value - 12 months or greater	4,287	11,026
Unrealized Losses - 12 months or greater	-315	-537
Fair Value - Less than 12 months	5,319	115
Unrealized Losses - Less than 12 months	-83	-33
Total Fair Value of Securities in Unrealized Loss Position	9,606	11,141
Total Unrealized Losses	-398	-570
ABS [Member]	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'
Fair Value - 12 months or greater	37,765	99,514
Unrealized Losses - 12 months or greater	-2,941	-7,034
Fair Value - Less than 12 months	553,803	39,296
Unrealized Losses - Less than 12 months	-5,753	-148
Total Fair Value of Securities in Unrealized Loss Position	591,568	138,810
Total Unrealized Losses	-8,694	-7,182
Municipals [Member]	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'
Fair Value - 12 months or greater	8,408	6,386
Unrealized Losses - 12 months or greater	-615	-270
Fair Value - Less than 12 months	543,474	77,766
Unrealized Losses - Less than 12 months	-13,901	-455
Total Fair Value of Securities in Unrealized Loss Position	551,882	84,152
Total Unrealized Losses	-14,516	-725
Equity Securities [Member]	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'
Fair Value - 12 months or greater	3,499	11,554
Unrealized Losses - 12 months or greater	-398	-1,793
Fair Value - Less than 12 months	48,828	95,697
Unrealized Losses - Less than 12 months	-5,785	-5,605
Total Fair Value of Securities in Unrealized Loss Position	52,327	107,251
Total Unrealized Losses	-6,183	-7,398
Number of Available For Sale Securities In Unrealized Loss Positions	63	106
Number of Available For Sale Securities in Unrealized Loss Positions for 12 Months or Greater	9	17
Common Stock [Member]	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'
Fair Value - 12 months or greater	3,499	11,554
Unrealized Losses - 12 months or greater	-398	-1,793
Fair Value - Less than 12 months	48,828	95,697
Unrealized Losses - Less than 12 months	-5,785	-5,605
Total Fair Value of Securities in Unrealized Loss Position	52,327	107,251
Total Unrealized Losses	($6,183)	($7,398)

INVESTMENTS_DETAILS_4

INVESTMENTS (DETAILS 4) (USD $)

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Nov. 21, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Aug. 01, 2013

Hedge funds [Member]

Hedge funds [Member]

Hedge funds [Member]

Hedge funds [Member]

Long/short equity funds [Member]

Long/short equity funds [Member]

Long/short equity funds [Member]

Long/short equity funds [Member]

Long/short equity funds [Member]

Long/short equity funds [Member]

Multi-strategy funds [Member]

Multi-strategy funds [Member]

Multi-strategy funds [Member]

Multi-strategy funds [Member]

Multi-strategy funds [Member]

Multi-strategy funds [Member]

Multi-strategy funds [Member]

Event driven funds [Member]

Event driven funds [Member]

Event driven funds [Member]

Event driven funds [Member]

Event driven funds [Member]

Event driven funds [Member]

Leveraged bank loan funds [Member]

Leveraged bank loan funds [Member]

Direct Lending Funds [Member]

Direct Lending Funds [Member]

Direct Lending Funds [Member]

Direct Lending Funds [Member]

Direct Lending Funds [Member]

Direct Lending Funds [Member]

CLO-Equities [Member]

CLO-Equities [Member]

CLO-Equities [Member]

Lockup Redemption Restriction [Member]

Lockup Redemption Restriction [Member]

Other Redemption Restriction [Member]

Other Redemption Restriction [Member]

Minimum [Member]

Minimum [Member]

Maximum [Member]

Maximum [Member]

Other Redemption Restriction [Member]

Minimum [Member]

Minimum [Member]

Maximum [Member]

Maximum [Member]

Minimum [Member]

Minimum [Member]

Maximum [Member]

Maximum [Member]

Other Redemption Restriction [Member]

Other Redemption Restriction [Member]

Minimum [Member]

Maximum [Member]

Other Redemption Restriction [Member]

Other Investments [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Other investments

$1,045,810,000

$843,437,000

'

'

'

'

$425,444,000

$302,680,000

'

'

'

'

$285,155,000

$244,075,000

'

'

'

'

'

$190,458,000

$171,479,000

'

'

'

'

$48,753,000

$62,768,000

$22,134,000

$0

'

'

'

'

$73,866,000

$62,435,000

'

Percentage of total fair value

100.00%

100.00%

'

'

'

'

41.00%

36.00%

'

'

'

'

27.00%

29.00%

'

'

'

'

'

18.00%

20.00%

'

'

'

'

5.00%

8.00%

2.00%

0.00%

'

'

'

'

7.00%

7.00%

'

Redemption frequency

'

'

'

'

'

'

'Monthly, Quarterly, Semi-annually

'Monthly, Quarterly, Semi-annually

'

'

'

'

'Quarterly, Semi-annually

'Quarterly, Semi-annually

'

'

'

'

'

'Quarterly, Annually

'Quarterly, Annually

'

'

'

'

'Quarterly

'Quarterly

'

'

'

'

'

'

'

'

'

Redemption notice period

'

'

'

'

'

'

'

'

'30 days

'30 days

'60 days

'60 days

'

'

'

'60 days

'60 days

'95 days

'95 days

'

'

'45 days

'45 days

'60 days

'95 days

'65 days

'65 days

'

'

'

'

'

'

'

'

'

Fair value of other investments subject to redemption restrictions

'

'

99,000,000

38,000,000

11,000,000

29,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

22,134,000

0

'

'

'

'

'

Percentage of fair value of other investments subject to redemption restrictions

'

'

10.00%

5.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2.00%

0.00%

'

'

'

'

'

Unfunded commitments related to other investments

'

'

'

'

'

'

'

'

'

'

'

'

$54,000,000

'

$60,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$88,000,000

$40,000,000

'

'

$27,000,000

'

$60,000,000

Investment term

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'5 years

'10 years

'

'

'

Optional extension of investment term

'

'

'

'

'

'

'

'

'

'

'

'

'3 years

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'3 years

'

'

'

'

'

'

'

'

INVESTMENTS_DETAILS_5

INVESTMENTS (DETAILS 5) (USD $)	3 Months Ended								12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Net Investment Income [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Gross investment income	'	'	'	'	'	'	'	'	$440,838	$409,088	$387,947
Investment expenses	'	'	'	'	'	'	'	'	-31,526	-28,131	-25,517
Net investment income	113,863	103,429	83,112	108,908	86,847	103,638	74,449	116,023	409,312	380,957	362,430
Fixed Maturities [Member]	'	'	'	'	'	'	'	'	'	'	'
Net Investment Income [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Gross investment income	'	'	'	'	'	'	'	'	293,609	304,400	337,616
Other Investments [Member]	'	'	'	'	'	'	'	'	'	'	'
Net Investment Income [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Gross investment income	'	'	'	'	'	'	'	'	128,814	87,660	31,856
Equity Securities [Member]	'	'	'	'	'	'	'	'	'	'	'
Net Investment Income [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Gross investment income	'	'	'	'	'	'	'	'	10,897	11,904	11,186
Cash And Cash Equivalents [Member]	'	'	'	'	'	'	'	'	'	'	'
Net Investment Income [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Gross investment income	'	'	'	'	'	'	'	'	6,337	4,528	5,697
Short-term Investments [Member]	'	'	'	'	'	'	'	'	'	'	'
Net Investment Income [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Gross investment income	'	'	'	'	'	'	'	'	$1,181	$596	$1,592

INVESTMENTS_DETAILS_6

INVESTMENTS (DETAILS 6) (USD $)	3 Months Ended								12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Schedule Of Available For Sale Securities [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Gross realized gains	'	'	'	'	'	'	'	'	$175,496	$278,493	$260,288
Gross realized losses	'	'	'	'	'	'	'	'	-98,301	-125,374	-123,016
Net OTTI recognized in earnings	'	'	'	'	'	'	'	'	-9,362	-24,234	-15,861
Change in fair value of investment derivatives	'	'	'	'	'	'	'	'	7,731	-9,170	4,431
Fair value hedges	'	'	'	'	'	'	'	'	0	7,754	-4,403
Total net realized investment gains	19,558	-4,708	16,235	44,478	31,771	50,803	30,405	14,491	75,564	127,469	121,439
Fair Value Hedging [Member]	'	'	'	'	'	'	'	'	'	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Gross realized gains	'	'	'	'	'	'	'	'	'	37,000	'
Gross realized losses	'	'	'	'	'	'	'	'	'	'	-11,000
Fixed Maturities And Short-Term Investments [Member]	'	'	'	'	'	'	'	'	'	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Gross realized gains	'	'	'	'	'	'	'	'	120,932	242,082	243,296
Gross realized losses	'	'	'	'	'	'	'	'	-87,894	-101,844	-108,490
Equity Securities [Member]	'	'	'	'	'	'	'	'	'	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Gross realized gains	'	'	'	'	'	'	'	'	54,564	36,411	16,992
Gross realized losses	'	'	'	'	'	'	'	'	($10,407)	($23,530)	($14,526)

INVESTMENTS_DETAILS_7

INVESTMENTS (DETAILS 7) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Other Than Temporary Impairment Losses Investments Portion Recognized In Earnings Net [Line Items]	'	'	'
Total OTTI recognized in earnings	$9,362	$24,234	$15,861
Fixed Maturities [Member]	'	'	'
Other Than Temporary Impairment Losses Investments Portion Recognized In Earnings Net [Line Items]	'	'	'
Total OTTI recognized in earnings	6,747	7,913	3,215
Non-US Government [Member]	'	'	'
Other Than Temporary Impairment Losses Investments Portion Recognized In Earnings Net [Line Items]	'	'	'
Total OTTI recognized in earnings	120	3,281	0
Corporate Debt [Member]	'	'	'
Other Than Temporary Impairment Losses Investments Portion Recognized In Earnings Net [Line Items]	'	'	'
Total OTTI recognized in earnings	5,802	1,821	1,954
Non-Agency RMBS [Member]	'	'	'
Other Than Temporary Impairment Losses Investments Portion Recognized In Earnings Net [Line Items]	'	'	'
Total OTTI recognized in earnings	57	2,016	717
ABS [Member]	'	'	'
Other Than Temporary Impairment Losses Investments Portion Recognized In Earnings Net [Line Items]	'	'	'
Total OTTI recognized in earnings	129	795	61
Municipals [Member]	'	'	'
Other Than Temporary Impairment Losses Investments Portion Recognized In Earnings Net [Line Items]	'	'	'
Total OTTI recognized in earnings	639	0	483
Equity Securities [Member]	'	'	'
Other Than Temporary Impairment Losses Investments Portion Recognized In Earnings Net [Line Items]	'	'	'
Total OTTI recognized in earnings	2,615	16,321	12,646
Common Stock [Member]	'	'	'
Other Than Temporary Impairment Losses Investments Portion Recognized In Earnings Net [Line Items]	'	'	'
Total OTTI recognized in earnings	2,092	7,318	12,646
Exchange-Traded Funds [Member]	'	'	'
Other Than Temporary Impairment Losses Investments Portion Recognized In Earnings Net [Line Items]	'	'	'
Total OTTI recognized in earnings	$523	$9,003	$0

INVESTMENTS_DETAILS_8

INVESTMENTS (DETAILS 8) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Credit Losses For Which a Portion of OTTI Was Recognized in AOCI [Roll Forward]	'	'
Balance at beginning of period	$1,809	$2,061
Credit impairments recognized on securities not previously impaired	0	0
Additional credit impairments recognized on securities previously impaired	0	0
Change in timing of future cash flows on securities previously impaired	0	0
Intent to sell of securities previously impaired	0	0
Securities sold/redeemed/matured	-215	-252
Balance at end of period	$1,594	$1,809

INVESTMENTS_DETAILS_9

INVESTMENTS (DETAILS 9) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Schedule Of Available For Sale Securities [Line Items]	'	'	'
Fair Value (fixed maturities)	$11,986,327	$11,928,049	'
Decrease in credit loss impairments due to maturity	215	252	'
Realized gains on maturity	175,496	278,493	260,288
Non-US Government [Member]	'	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'	'
Fair Value (fixed maturities)	1,176,382	1,104,576	'
Non-US Government [Member] | eurozone [Member]	'	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'	'
Fair Value (fixed maturities)	161,000	217,000	'
CMBS [Member]	'	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'	'
Fair Value (fixed maturities)	797,414	840,084	'
CMBS [Member] | Weighted Average [Member]	'	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'	'
Subordination percentage input for determining credit losses	30.00%	30.00%	'
Non-Agency RMBS [Member]	'	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'	'
Fair Value (fixed maturities)	67,567	95,199	'
Non-Agency RMBS [Member] | Prime [Member]	'	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'	'
Fair Value (fixed maturities)	41,000	65,000	'
Non-Agency RMBS [Member] | Alt A [Member]	'	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'	'
Fair Value (fixed maturities)	19,000	22,000	'
CLO Debt Tranched Securities [Member]	'	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'	'
Fair Value (fixed maturities)	$30,000	$53,000	'
Default rate input for determining credit losses	4.00%	4.00%	'
Loss severity rate input for determining credit losses	53.50%	53.50%	'
CLO Debt Tranched Securities [Member] | Minimum [Member]	'	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'	'
Collateral spread input for determining credit losses	2.70%	2.50%	'
CLO Debt Tranched Securities [Member] | Maximum [Member]	'	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'	'
Collateral spread input for determining credit losses	3.50%	3.70%	'

INVESTMENTS_DETAILS_10

INVESTMENTS (DETAILS 10) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Investments, Debt and Equity Securities [Abstract]	'	'
Collateral in Trust for inter-company agreements	$2,261,081	$2,134,931
Collateral for secured letter of credit facility	777,828	470,062
Collateral in Trust for third party agreements	276,839	245,539
Securities on deposit with regulatory authorities	58,327	59,456
Total restricted investments	$3,374,075	$2,909,988

INVESTMENTS_DETAILS_11

INVESTMENTS (DETAILS 11) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Investments, Debt and Equity Securities [Abstract]	'	'
Value of reverse repurchase agreements	$34	$39
Minimum required collateral for reverse repurchase agreements, expressed as a percentage of loan principal	102.00%	'

FAIR_VALUE_MEASUREMENTS_DETAIL

FAIR VALUE MEASUREMENTS (DETAILS) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	$11,986,327	$11,928,049
Equity securities	701,987	666,548
Other investments	1,045,810	843,437
Short-term investments	46,212	108,860
Derivative assets (see Note 7)	7,808	5,838
Derivative liabilities (see Note 7)	1,967	3,737
Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	11,986,327	11,928,049
Equity securities	701,987	666,548
Other investments	1,045,810	843,437
Short-term investments	46,212	108,860
Derivative assets (see Note 7)	7,808	5,838
Total assets	13,788,144	13,552,732
Derivative liabilities (see Note 7)	1,967	3,737
Cash settled awards (see Note 16)	8,693	0
Total liabilities	10,660	3,737
US Government and Agency [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	1,388,698	1,422,885
US Government and Agency [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	1,388,698	1,422,885
Non-US Government [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	1,176,382	1,104,576
Non-US Government [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	1,176,382	1,104,576
Corporate Debt [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	3,608,238	3,876,382
Corporate Debt [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	3,608,238	3,876,382
Agency RMBS [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	2,448,827	2,659,908
Agency RMBS [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	2,448,827	2,659,908
CMBS [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	797,414	840,084
CMBS [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	797,414	840,084
Non-Agency RMBS [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	67,567	95,199
Non-Agency RMBS [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	67,567	95,199
ABS [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	953,451	643,206
ABS [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	953,451	643,206
Municipals [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	1,545,750	1,285,809
Municipals [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	1,545,750	1,285,809
Common Stock [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Equity securities	438,318	443,398
Common Stock [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Equity securities	438,318	443,398
Exchange-Traded Funds [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Equity securities	138,847	119,161
Exchange-Traded Funds [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Equity securities	138,847	119,161
Non-U.S. Bond Mutual Funds [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Equity securities	124,822	103,989
Non-U.S. Bond Mutual Funds [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Equity securities	124,822	103,989
Hedge funds [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Other investments	949,810	781,002
Direct Lending Funds [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Other investments	22,134	0
CLO-Equities [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Other investments	73,866	62,435
Level 1 [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	1,119,632	1,094,220
Equity securities	577,165	562,559
Other investments	0	0
Short-term investments	0	0
Derivative assets (see Note 7)	0	0
Total assets	1,696,797	1,656,779
Derivative liabilities (see Note 7)	0	0
Cash settled awards (see Note 16)	0	0
Total liabilities	0	0
Level 1 [Member] | US Government and Agency [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	1,119,632	1,094,220
Level 1 [Member] | Non-US Government [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	0	0
Level 1 [Member] | Corporate Debt [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	0	0
Level 1 [Member] | Agency RMBS [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	0	0
Level 1 [Member] | CMBS [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	0	0
Level 1 [Member] | Non-Agency RMBS [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	0	0
Level 1 [Member] | ABS [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	0	0
Level 1 [Member] | Municipals [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	0	0
Level 1 [Member] | Common Stock [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Equity securities	438,318	443,398
Level 1 [Member] | Exchange-Traded Funds [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Equity securities	138,847	119,161
Level 1 [Member] | Non-U.S. Bond Mutual Funds [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Equity securities	0	0
Level 1 [Member] | Hedge funds [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Other investments	0	0
Level 1 [Member] | Direct Lending Funds [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Other investments	0	0
Level 1 [Member] | CLO-Equities [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Other investments	0	0
Level 2 [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	10,831,878	10,762,898
Equity securities	124,822	103,989
Other investments	488,755	421,006
Short-term investments	46,212	108,860
Derivative assets (see Note 7)	6,824	5,838
Total assets	11,498,491	11,402,591
Derivative liabilities (see Note 7)	1,152	3,737
Cash settled awards (see Note 16)	8,693	0
Total liabilities	9,845	3,737
Level 2 [Member] | US Government and Agency [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	269,066	328,665
Level 2 [Member] | Non-US Government [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	1,176,382	1,104,576
Level 2 [Member] | Corporate Debt [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	3,608,238	3,874,832
Level 2 [Member] | Agency RMBS [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	2,448,827	2,659,908
Level 2 [Member] | CMBS [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	793,396	835,788
Level 2 [Member] | Non-Agency RMBS [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	67,567	94,089
Level 2 [Member] | ABS [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	922,652	579,231
Level 2 [Member] | Municipals [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	1,545,750	1,285,809
Level 2 [Member] | Common Stock [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Equity securities	0	0
Level 2 [Member] | Exchange-Traded Funds [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Equity securities	0	0
Level 2 [Member] | Non-U.S. Bond Mutual Funds [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Equity securities	124,822	103,989
Level 2 [Member] | Hedge funds [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Other investments	488,755	421,006
Level 2 [Member] | Direct Lending Funds [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Other investments	0	0
Level 2 [Member] | CLO-Equities [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Other investments	0	0
Level 3 [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	34,817	70,931
Equity securities	0	0
Other investments	557,055	422,431
Short-term investments	0	0
Derivative assets (see Note 7)	984	0
Total assets	592,856	493,362
Derivative liabilities (see Note 7)	815	0
Cash settled awards (see Note 16)	0	0
Total liabilities	815	0
Level 3 [Member] | US Government and Agency [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	0	0
Level 3 [Member] | Non-US Government [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	0	0
Level 3 [Member] | Corporate Debt [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	0	1,550
Level 3 [Member] | Agency RMBS [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	0	0
Level 3 [Member] | CMBS [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	4,018	4,296
Level 3 [Member] | Non-Agency RMBS [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	0	1,110
Level 3 [Member] | ABS [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	30,799	63,975
Level 3 [Member] | Municipals [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	0	0
Level 3 [Member] | Common Stock [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Equity securities	0	0
Level 3 [Member] | Exchange-Traded Funds [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Equity securities	0	0
Level 3 [Member] | Non-U.S. Bond Mutual Funds [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Equity securities	0	0
Level 3 [Member] | Hedge funds [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Other investments	461,055	359,996
Level 3 [Member] | Direct Lending Funds [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Other investments	22,134	0
Level 3 [Member] | CLO-Equities [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Other investments	$73,866	$62,435

FAIR_VALUE_MEASUREMENTS_DETAIL1

FAIR VALUE MEASUREMENTS (DETAILS 2) (USD $)

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

In Thousands, unless otherwise specified

Level 3 [Member]

Level 3 [Member]

Discounted cash flow [Member]

Discounted cash flow [Member]

Broker-dealer quote [Member]

Net asset value [Member]

Simulation model [Member]

Minimum [Member]

Minimum [Member]

Minimum [Member]

Maximum [Member]

Maximum [Member]

Maximum [Member]

Weighted Average [Member]

Weighted Average [Member]

ABS - CLO Debt [Member]

Other Investments - CLO-Equities [Member]

Level 3 [Member]

Level 3 [Member]

Level 3 [Member]

Level 3 [Member]

Level 3 [Member]

Discounted cash flow [Member]

Discounted cash flow [Member]

Simulation model [Member]

Discounted cash flow [Member]

Discounted cash flow [Member]

Simulation model [Member]

Discounted cash flow [Member]

Discounted cash flow [Member]

ABS - CLO Debt [Member]

Other Investments - CLO-Equities [Member]

ABS - CLO Debt [Member]

Other Investments - CLO-Equities [Member]

Weather Related Derivative [Member]

Level 3 [Member]

Level 3 [Member]

Level 3 [Member]

Level 3 [Member]

Level 3 [Member]

Level 3 [Member]

Level 3 [Member]

Level 3 [Member]

ABS - CLO Debt [Member]

Other Investments - CLO-Equities [Member]

Weather Related Derivative [Member]

ABS - CLO Debt [Member]

Other Investments - CLO-Equities [Member]

Weather Related Derivative [Member]

ABS - CLO Debt [Member]

Other Investments - CLO-Equities [Member]

Fair Value Inputs Assets Quantitative Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Fixed maturities

$11,986,327

$11,928,049

$30,799

'

$29,944

'

$855

'

'

'

'

'

'

'

'

'

'

Other investments

1,045,810

843,437

'

73,866

'

39,706

'

34,160

'

'

'

'

'

'

'

'

'

Net derivative assets

'

'

'

'

'

'

'

'

$169

'

'

'

'

'

'

'

'

Credit spread

'

'

'

'

'

'

'

'

'

3.30%

'

'

4.60%

'

'

3.70%

'

Illiquidity discount

'

'

'

'

5.00%

'

'

'

'

'

'

'

'

'

'

5.00%

'

Default rates

'

'

'

'

'

'

'

'

'

'

4.00%

'

'

5.00%

'

'

4.40%

Loss severity rate

'

'

'

'

'

53.50%

'

'

'

'

'

'

'

'

'

'

53.50%

Collateral spreads

'

'

'

'

'

'

'

'

'

'

2.60%

'

'

3.40%

'

'

3.30%

Estimated maturity dates (years)

'

'

'

'

'

'

'

'

'

'

'2 years 37 days

'

'

'4 years 219 days

'

'

'4 years 73 days

Weather curve

'

'

'

'

'

'

'

'

'

'

'

525

'

'

4,750

'

'

Weather standard deviation

'

'

'

'

'

'

'

'

'

'

'

94

'

'

290

'

'

FAIR_VALUE_MEASUREMENTS_DETAIL2

FAIR VALUE MEASUREMENTS (DETAILS 3) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Fixed Maturities [Member]	'	'
Changes in Level 3 Financial Instruments Measured at Fair Value on a Recurring Basis [Line Items]	'	'
Balance at beginning of period	$70,931	$50,878
Transfers into Level 3	0	15,945
Transfers out of Level 3	-1,222	0
Included in earnings	1,439	0
Included in OCI	1,651	5,112
Purchases	0	0
Sales	0	0
Settlements / distributions	-37,982	-1,004
Balance at end of period	34,817	70,931
Change in unrealized investment gain/(loss) relating to assets held at the reporting date	0	0
Other Investments [Member]	'	'
Changes in Level 3 Financial Instruments Measured at Fair Value on a Recurring Basis [Line Items]	'	'
Balance at beginning of period	422,431	412,804
Transfers into Level 3	0	0
Transfers out of Level 3	0	-9,435
Included in earnings	86,066	64,409
Included in OCI	0	0
Purchases	142,471	0
Sales	0	-2,835
Settlements / distributions	-93,913	-42,512
Balance at end of period	557,055	422,431
Change in unrealized investment gain/(loss) relating to assets held at the reporting date	86,066	64,409
Other Assets [Member]	'	'
Changes in Level 3 Financial Instruments Measured at Fair Value on a Recurring Basis [Line Items]	'	'
Balance at beginning of period	0	0
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Included in earnings	2,084	0
Included in OCI	0	0
Purchases	-1,100	0
Sales	0	0
Settlements / distributions	0	0
Balance at end of period	984	0
Change in unrealized investment gain/(loss) relating to assets held at the reporting date	2,084	0
Total Assets [Member]	'	'
Changes in Level 3 Financial Instruments Measured at Fair Value on a Recurring Basis [Line Items]	'	'
Balance at beginning of period	493,362	463,682
Transfers into Level 3	0	15,945
Transfers out of Level 3	-1,222	-9,435
Included in earnings	89,589	64,409
Included in OCI	1,651	5,112
Purchases	141,371	0
Sales	0	-2,835
Settlements / distributions	-131,895	-43,516
Balance at end of period	592,856	493,362
Change in unrealized investment gain/(loss) relating to assets held at the reporting date	88,150	64,409
Total Liabilities [Member]	'	'
Changes in Level 3 Financial Instruments Measured at Fair Value on a Recurring Basis [Line Items]	'	'
Balance at beginning of period	0	0
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Included in earnings	98	0
Included in OCI	0	0
Purchases	717	0
Sales	0	0
Settlements / distributions	0	0
Balance at end of period	815	0
Change in unrealized investment gain/(loss) relating to assets held at the reporting date	98	0
Corporate Debt [Member] | Fixed Maturities [Member]	'	'
Changes in Level 3 Financial Instruments Measured at Fair Value on a Recurring Basis [Line Items]	'	'
Balance at beginning of period	1,550	1,550
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Included in earnings	1,550	0
Included in OCI	0	0
Purchases	0	0
Sales	0	0
Settlements / distributions	-3,100	0
Balance at end of period	0	1,550
Change in unrealized investment gain/(loss) relating to assets held at the reporting date	0	0
Non-Agency RMBS [Member] | Fixed Maturities [Member]	'	'
Changes in Level 3 Financial Instruments Measured at Fair Value on a Recurring Basis [Line Items]	'	'
Balance at beginning of period	1,110	0
Transfers into Level 3	0	1,110
Transfers out of Level 3	-1,222	0
Included in earnings	0	0
Included in OCI	135	0
Purchases	0	0
Sales	0	0
Settlements / distributions	-23	0
Balance at end of period	0	1,110
Change in unrealized investment gain/(loss) relating to assets held at the reporting date	0	0
CMBS [Member] | Fixed Maturities [Member]	'	'
Changes in Level 3 Financial Instruments Measured at Fair Value on a Recurring Basis [Line Items]	'	'
Balance at beginning of period	4,296	0
Transfers into Level 3	0	4,296
Transfers out of Level 3	0	0
Included in earnings	0	0
Included in OCI	-278	0
Purchases	0	0
Sales	0	0
Settlements / distributions	0	0
Balance at end of period	4,018	4,296
Change in unrealized investment gain/(loss) relating to assets held at the reporting date	0	0
ABS [Member] | Fixed Maturities [Member]	'	'
Changes in Level 3 Financial Instruments Measured at Fair Value on a Recurring Basis [Line Items]	'	'
Balance at beginning of period	63,975	49,328
Transfers into Level 3	0	10,539
Transfers out of Level 3	0	0
Included in earnings	-111	0
Included in OCI	1,794	5,112
Purchases	0	0
Sales	0	0
Settlements / distributions	-34,859	-1,004
Balance at end of period	30,799	63,975
Change in unrealized investment gain/(loss) relating to assets held at the reporting date	0	0
Hedge funds [Member] | Other Investments [Member]	'	'
Changes in Level 3 Financial Instruments Measured at Fair Value on a Recurring Basis [Line Items]	'	'
Balance at beginning of period	359,996	346,244
Transfers into Level 3	0	0
Transfers out of Level 3	0	-9,435
Included in earnings	58,293	33,301
Included in OCI	0	0
Purchases	86,138	0
Sales	0	-2,835
Settlements / distributions	-43,372	-7,279
Balance at end of period	461,055	359,996
Change in unrealized investment gain/(loss) relating to assets held at the reporting date	58,293	33,301
Direct Lending Funds [Member] | Other Investments [Member]	'	'
Changes in Level 3 Financial Instruments Measured at Fair Value on a Recurring Basis [Line Items]	'	'
Balance at beginning of period	0	0
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Included in earnings	-125	0
Included in OCI	0	0
Purchases	22,317	0
Sales	0	0
Settlements / distributions	-58	0
Balance at end of period	22,134	0
Change in unrealized investment gain/(loss) relating to assets held at the reporting date	-125	0
CLO-Equities [Member] | Other Investments [Member]	'	'
Changes in Level 3 Financial Instruments Measured at Fair Value on a Recurring Basis [Line Items]	'	'
Balance at beginning of period	62,435	66,560
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Included in earnings	27,898	31,108
Included in OCI	0	0
Purchases	34,016	0
Sales	0	0
Settlements / distributions	-50,483	-35,233
Balance at end of period	73,866	62,435
Change in unrealized investment gain/(loss) relating to assets held at the reporting date	27,898	31,108
Derivative [Member] | Other Assets [Member]	'	'
Changes in Level 3 Financial Instruments Measured at Fair Value on a Recurring Basis [Line Items]	'	'
Balance at beginning of period	0	0
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Included in earnings	2,084	0
Included in OCI	0	0
Purchases	-1,100	0
Sales	0	0
Settlements / distributions	0	0
Balance at end of period	984	0
Change in unrealized investment gain/(loss) relating to assets held at the reporting date	2,084	0
Derivative [Member] | Other Liabilities [Member]	'	'
Changes in Level 3 Financial Instruments Measured at Fair Value on a Recurring Basis [Line Items]	'	'
Balance at beginning of period	0	0
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Included in earnings	98	0
Included in OCI	0	0
Purchases	717	0
Sales	0	0
Settlements / distributions	0	0
Balance at end of period	815	0
Change in unrealized investment gain/(loss) relating to assets held at the reporting date	$98	$0

FAIR_VALUE_MEASUREMENTS_DETAIL3

FAIR VALUE MEASUREMENTS (DETAILS 4) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]	'	'
Senior notes	$995,855	$995,245
Estimate Of Fair Value [Member]	'	'
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]	'	'
Senior notes	$1,073,000	$1,091,000

DERIVATIVE_INSTRUMENTS_DETAILS

DERIVATIVE INSTRUMENTS (DETAILS) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Derivative Fair Values on Consolidated Balance Sheet [Line Items]	'	'
Asset Derivative Fair Value	$7,808	$5,838
Liability Derivative Fair Value	1,967	3,737
Other Assets [Member]	'	'
Derivative Fair Values on Consolidated Balance Sheet [Line Items]	'	'
Asset Derivative Fair Value	7,808	5,838
Other Liabilities [Member]	'	'
Derivative Fair Values on Consolidated Balance Sheet [Line Items]	'	'
Liability Derivative Fair Value	1,967	3,737
Investment Portfolio [Member] | Foreign Exchange Forward Contracts [Member] | Not Designated as Hedging Instruments [Member]	'	'
Derivative Fair Values on Consolidated Balance Sheet [Line Items]	'	'
Derivative Notional Amount	254,023	287,819
Investment Portfolio [Member] | Foreign Exchange Forward Contracts [Member] | Other Assets [Member] | Not Designated as Hedging Instruments [Member]	'	'
Derivative Fair Values on Consolidated Balance Sheet [Line Items]	'	'
Asset Derivative Fair Value	1,214	1,067
Investment Portfolio [Member] | Foreign Exchange Forward Contracts [Member] | Other Liabilities [Member] | Not Designated as Hedging Instruments [Member]	'	'
Derivative Fair Values on Consolidated Balance Sheet [Line Items]	'	'
Liability Derivative Fair Value	1,032	2,733
Investment Portfolio [Member] | Interest Rate Swap [Member] | Not Designated as Hedging Instruments [Member]	'	'
Derivative Fair Values on Consolidated Balance Sheet [Line Items]	'	'
Derivative Notional Amount	281,250	0
Investment Portfolio [Member] | Interest Rate Swap [Member] | Other Assets [Member] | Not Designated as Hedging Instruments [Member]	'	'
Derivative Fair Values on Consolidated Balance Sheet [Line Items]	'	'
Asset Derivative Fair Value	873	0
Investment Portfolio [Member] | Interest Rate Swap [Member] | Other Liabilities [Member] | Not Designated as Hedging Instruments [Member]	'	'
Derivative Fair Values on Consolidated Balance Sheet [Line Items]	'	'
Liability Derivative Fair Value	0	0
Underwriting Portfolio [Member] | Foreign Exchange Forward Contracts [Member] | Not Designated as Hedging Instruments [Member]	'	'
Derivative Fair Values on Consolidated Balance Sheet [Line Items]	'	'
Derivative Notional Amount	390,663	476,191
Underwriting Portfolio [Member] | Foreign Exchange Forward Contracts [Member] | Other Assets [Member] | Not Designated as Hedging Instruments [Member]	'	'
Derivative Fair Values on Consolidated Balance Sheet [Line Items]	'	'
Asset Derivative Fair Value	4,737	4,771
Underwriting Portfolio [Member] | Foreign Exchange Forward Contracts [Member] | Other Liabilities [Member] | Not Designated as Hedging Instruments [Member]	'	'
Derivative Fair Values on Consolidated Balance Sheet [Line Items]	'	'
Liability Derivative Fair Value	120	1,004
Underwriting Portfolio [Member] | Weather Related Derivative [Member] | Not Designated as Hedging Instruments [Member]	'	'
Derivative Fair Values on Consolidated Balance Sheet [Line Items]	'	'
Derivative Notional Amount	24,451	0
Underwriting Portfolio [Member] | Weather Related Derivative [Member] | Other Assets [Member] | Not Designated as Hedging Instruments [Member]	'	'
Derivative Fair Values on Consolidated Balance Sheet [Line Items]	'	'
Asset Derivative Fair Value	984	0
Underwriting Portfolio [Member] | Weather Related Derivative [Member] | Other Liabilities [Member] | Not Designated as Hedging Instruments [Member]	'	'
Derivative Fair Values on Consolidated Balance Sheet [Line Items]	'	'
Liability Derivative Fair Value	$815	$0

DERIVATIVE_INSTRUMENTS_DETAILS1

DERIVATIVE INSTRUMENTS (DETAILS 2) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'	'
Derivative assets - gross amounts	$9,796	$6,476
Derivative assets - gross amounts offset	-1,988	-639
Asset Derivative Fair Value	7,808	5,838
Derivative liabilities - gross amounts	3,955	4,376
Derivative liabilities - gross amounts offset	-1,988	-639
Liability Derivative Fair Value	$1,967	$3,737

DERIVATIVE_INSTRUMENTS_DETAILS2

DERIVATIVE INSTRUMENTS (DETAILS 3) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'	'	'
Foreign exchange forward contracts	$0	$10,853	$11,682
Hedged investment portfolio	0	-3,099	-16,085
Hedge ineffectiveness recognized in earnings	$0	$7,754	($4,403)

DERIVATIVE_INSTRUMENTS_DETAILS3

DERIVATIVE INSTRUMENTS (DETAILS 4) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Unrealized and Realized Gains (Losses) Recognized in Earnings for Derivatives Not Designated As Hedges [Line Items]	'	'	'
Unrealized and realized gains (losses) recognized in earnings for derivatives not designated as hedges	$11,408	$17,442	$38,591
Investment Portfolio [Member] | Foreign Exchange Forward Contracts [Member] | Net Realized Investment Gains (Losses) [Member]	'	'	'
Unrealized and Realized Gains (Losses) Recognized in Earnings for Derivatives Not Designated As Hedges [Line Items]	'	'	'
Unrealized and realized gains (losses) recognized in earnings for derivatives not designated as hedges	10,843	-9,170	4,431
Investment Portfolio [Member] | Interest Rate Swap [Member] | Net Realized Investment Gains (Losses) [Member]	'	'	'
Unrealized and Realized Gains (Losses) Recognized in Earnings for Derivatives Not Designated As Hedges [Line Items]	'	'	'
Unrealized and realized gains (losses) recognized in earnings for derivatives not designated as hedges	-3,112	0	0
Underwriting Portfolio [Member] | Foreign Exchange Forward Contracts [Member] | Foreign Exchange Gains (Losses) [Member]	'	'	'
Unrealized and Realized Gains (Losses) Recognized in Earnings for Derivatives Not Designated As Hedges [Line Items]	'	'	'
Unrealized and realized gains (losses) recognized in earnings for derivatives not designated as hedges	1,690	26,612	33,893
Underwriting Portfolio [Member] | Currency Collar Options [Member] | Foreign Exchange Gains (Losses) [Member]	'	'	'
Unrealized and Realized Gains (Losses) Recognized in Earnings for Derivatives Not Designated As Hedges [Line Items]	'	'	'
Unrealized and realized gains (losses) recognized in earnings for derivatives not designated as hedges	0	0	267
Underwriting Portfolio [Member] | Weather Related Derivative [Member] | Other Insurance Related Income [Member]	'	'	'
Unrealized and Realized Gains (Losses) Recognized in Earnings for Derivatives Not Designated As Hedges [Line Items]	'	'	'
Unrealized and realized gains (losses) recognized in earnings for derivatives not designated as hedges	$1,987	$0	$0

RESERVE_FOR_LOSSES_AND_LOSS_EX2

RESERVE FOR LOSSES AND LOSS EXPENSES (DETAILS) (USD $)	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
In Thousands, unless otherwise specified
Insurance Loss Reserves [Abstract]	'	'	'	'
Reserve for reported losses and loss expenses	$3,499,817	$3,272,682	'	'
Reserve for losses incurred but not reported	6,082,323	5,786,049	'	'
Reserve for losses and loss expenses	$9,582,140	$9,058,731	$8,425,045	$7,032,375

RESERVE_FOR_LOSSES_AND_LOSS_EX3

RESERVE FOR LOSSES AND LOSS EXPENSES (DETAILS 2) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Reconciliation of Beginning and Ending Gross Unpaid Losses and Loss Expenses	'	'	'
Gross reserve for losses and loss expenses, beginning of period	$9,058,731	$8,425,045	$7,032,375
Less reinsurance recoverable on unpaid losses, beginning of period	-1,825,617	-1,736,823	-1,540,633
Net reserve for unpaid losses and loss expenses, beginning of period	7,233,114	6,688,222	5,491,742
Net incurred losses and loss expenses related to:	'	'	'
Current year	2,353,631	2,340,868	2,932,513
Prior years	-219,436	-244,840	-257,461
Net incurred losses and loss expenses	2,134,195	2,096,028	2,675,052
Net paid losses and loss expenses related to:	'	'	'
Current year	-318,006	-322,836	-509,075
Prior years	-1,373,459	-1,299,384	-953,035
Net paid losses and loss expenses	-1,691,465	-1,622,220	-1,462,110
Foreign exchange and other	6,184	71,084	-16,462
Net reserve for unpaid losses and loss expenses, end of period	7,682,028	7,233,114	6,688,222
Reinsurance recoverable on unpaid losses, end of period	1,900,112	1,825,617	1,736,823
Gross reserve for losses and loss expenses, end of period	$9,582,140	$9,058,731	$8,425,045

RESERVE_FOR_LOSSES_AND_LOSS_EX4

RESERVE FOR LOSSES AND LOSS EXPENSES (DETAILS 3) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Net Favorable Prior Year Reserve Development [Line Items]	'	'	'
Net favorable prior year reserve development	$219,436	$244,840	$257,461
Insurance [Member]	'	'	'
Net Favorable Prior Year Reserve Development [Line Items]	'	'	'
Net favorable prior year reserve development	50,355	122,209	103,014
Reinsurance [Member]	'	'	'
Net Favorable Prior Year Reserve Development [Line Items]	'	'	'
Net favorable prior year reserve development	$169,081	$122,631	$154,447

RESERVE_FOR_LOSSES_AND_LOSS_EX5

RESERVE FOR LOSSES AND LOSS EXPENSES (DETAILS 4) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Additional Information Related to Net Incurred Losses [Line Items]	'	'	'
Current year net loss and loss expenses	$2,353,631	$2,340,868	$2,932,513
Net favorable (adverse) prior year reserve development	219,436	244,840	257,461
Short Tail Lines Insurance And Reinsurance Business [Member]	'	'	'
Additional Information Related to Net Incurred Losses [Line Items]	'	'	'
Net favorable (adverse) prior year reserve development	162,000	186,000	178,000
Liability Reinsurance Business [Member]	'	'	'
Additional Information Related to Net Incurred Losses [Line Items]	'	'	'
Net favorable (adverse) prior year reserve development	85,000	'	'
Professional Lines Insurance And Reinsurance Business [Member]	'	'	'
Additional Information Related to Net Incurred Losses [Line Items]	'	'	'
Net favorable (adverse) prior year reserve development	-29,000	54,000	105,000
Professional Lines Insurance Business [Member]	'	'	'
Additional Information Related to Net Incurred Losses [Line Items]	'	'	'
Net favorable (adverse) prior year reserve development	-51,000	'	'
Catastrophe and Weather-related Events [Member]	'	'	'
Additional Information Related to Net Incurred Losses [Line Items]	'	'	'
Current year net loss and loss expenses	$201,000	$438,000	$944,000

REINSURANCE_DETAILS

REINSURANCE (DETAILS) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Premiums written:	'	'	'	'	'	'	'	'	'	'	'
Gross	'	'	'	'	'	'	'	'	$4,697,041,000	$4,139,643,000	$4,096,153,000
Ceded	'	'	'	'	'	'	'	'	-768,841,000	-802,187,000	-676,719,000
Net	'	'	'	'	'	'	'	'	3,928,200,000	3,337,456,000	3,419,434,000
Premiums earned:	'	'	'	'	'	'	'	'	'	'	'
Gross	'	'	'	'	'	'	'	'	4,459,269,000	4,141,037,000	3,973,956,000
Ceded	'	'	'	'	'	'	'	'	-752,204,000	-725,574,000	-658,995,000
Net	941,911,000	945,242,000	945,873,000	874,039,000	856,049,000	862,447,000	850,603,000	846,362,000	3,707,065,000	3,415,463,000	3,314,961,000
Reinsurance receivables:	'	'	'	'	'	'	'	'	'	'	'
Ceded losses and loss expenses	'	'	'	'	'	'	'	'	415,000,000	396,000,000	450,000,000
Provision for unrecoverable reinsurance	$18,000,000	'	'	'	$16,000,000	'	'	'	$18,000,000	$16,000,000	'
Percentage of gross reinsurance recoverables collectible from reinsurers rated A- or better by A.M. Best	98.80%	'	'	'	98.80%	'	'	'	98.80%	98.80%	'

DEBT_AND_FINANCING_ARRANGEMENT1

DEBT AND FINANCING ARRANGEMENTS (DETAILS) (Senior Notes [Member], USD $)	12 Months Ended			0 Months Ended		1 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Nov. 15, 2004	Dec. 31, 2013	Mar. 23, 2010	Dec. 31, 2013
				2004 AXIS Capital Holdings Limited Senior Notes [Member]	2004 AXIS Capital Holdings Limited Senior Notes [Member]	2010 AXIS Capital Finance LLC Senior Notes [Member]	2010 AXIS Capital Finance LLC Senior Notes [Member]
Senior notes [Line Items]	'	'	'	'	'	'	'
Face amount	'	'	'	'	$500	'	$500
Interest rate	'	'	'	'	5.75%	'	5.88%
Issue price (percentage of face amount)	'	'	'	99.79%	'	99.62%	'
Net proceeds on issuance	'	'	'	496	'	495	'
Percentage ownership in subsidiary	'	'	'	'	'	'	100.00%
Interest Expense	$59	$59	$59	'	'	'	'

DEBT_AND_FINANCIING_ARRANGEMEN

DEBT AND FINANCIING ARRANGEMENTS (DETAILS 2) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013
Letter of Credit Facility [Member] | Citibank [Member]	'
Line of Credit Facility [Line Items]	'
Maximum capacity	$750
Termination notice requirement for lender after agreed date	'30 days
Letters of credit outstanding	501
Letter of Credit Facility [Member] | ING [Member]	'
Line of Credit Facility [Line Items]	'
Maximum capacity	170
Letters of credit outstanding	170
Credit Facility [Member] | Syndication of Lenders [Member]	'
Line of Credit Facility [Line Items]	'
Maximum capacity	250
Potential increase in maximum capacity	150
Letters of credit outstanding	0
Credit facility borrowings	$0

COMMITMENTS_AND_CONTINGENCIES_1

COMMITMENTS AND CONTINGENCIES (DETAILS) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Commitments and Contingencies Disclosure [Abstract]	'	'
Fixed maturity portfolio - corporate issuer concentration limit A- above	2.00%	'
Fixed maturity portfolio - corporate issuer concentration limit below A-	1.00%	'
Premiums receivable allowance for doubtful accounts	$3	$2

COMMITMENTS_AND_CONTINGENCIES_2

COMMITMENTS AND CONTINGENCIES (DETAILS 2)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
	broker
Reinsurance Recoverable On Unpaid And Paid Losses [Member] | Credit Risk Concentration [Member] | Reinsurer 1 [Member]	'	'	'
Concentration Risk [Line Items]	'	'	'
Concentration risk, percentage of total	14.00%	13.00%	'
Reinsurance Recoverable On Unpaid And Paid Losses [Member] | Credit Risk Concentration [Member] | Reinsurer 2 [Member]	'	'	'
Concentration Risk [Line Items]	'	'	'
Concentration risk, percentage of total	11.00%	10.00%	'
Reinsurance Recoverable On Unpaid And Paid Losses [Member] | Credit Risk Concentration [Member] | Reinsurer 3 [Member]	'	'	'
Concentration Risk [Line Items]	'	'	'
Concentration risk, percentage of total	11.00%	10.00%	'
Reinsurance Recoverable On Unpaid And Paid Losses [Member] | Credit Risk Concentration [Member] | Top Ten Reinsurers [Member] | AM Best A Plus [Member]	'	'	'
Concentration Risk [Line Items]	'	'	'
Concentration risk, percentage of total	77.00%	72.00%	'
Gross Premiums Written [Member] | Customer Concentration [Member]	'	'	'
Concentration Risk [Line Items]	'	'	'
Concentration risk, percentage of total	61.00%	61.00%	63.00%
Concentration risk, number of brokers exceeding threshold	3	'	'
Gross Premiums Written [Member] | Customer Concentration [Member] | Aon Corporation [Member]	'	'	'
Concentration Risk [Line Items]	'	'	'
Concentration risk, percentage of total	26.00%	27.00%	27.00%
Gross Premiums Written [Member] | Customer Concentration [Member] | Marsh, Inc. [Member]	'	'	'
Concentration Risk [Line Items]	'	'	'
Concentration risk, percentage of total	23.00%	22.00%	23.00%
Gross Premiums Written [Member] | Customer Concentration [Member] | Willis Group Holdings Ltd. [Member]	'	'	'
Concentration Risk [Line Items]	'	'	'
Concentration risk, percentage of total	12.00%	12.00%	13.00%

COMMITMENTS_AND_CONTINGENCIES_3

COMMITMENTS AND CONTINGENCIES (DETAILS 3) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Commitments and Contingencies Disclosure [Abstract]	'	'	'
Rent expense related to operating leases	$29,000,000	$29,000,000	$24,000,000
Office Space [Member]	'	'	'
Future minimum lease payments under operating leases [Line Items]	'	'	'
2014	31,207,000	'	'
2015	27,378,000	'	'
2016	23,838,000	'	'
2017	20,881,000	'	'
2018	17,955,000	'	'
Later years	53,049,000	'	'
Total future minimum lease payments	$174,308,000	'	'

COMMITMENTS_AND_CONTINGENCIES_4

COMMITMENTS AND CONTINGENCIES (DETAILS 4) (USD $)	Dec. 31, 2013
In Millions, unless otherwise specified
Commitments and Contingencies Disclosure [Abstract]	'
Outstanding reinsurance purchase commitment	$80

EARNINGS_PER_COMMON_SHARE_DETA

EARNINGS PER COMMON SHARE (DETAILS) (USD $)	3 Months Ended								12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Basic earnings per common share	'	'	'	'	'	'	'	'	'	'	'
Net income	'	'	'	'	'	'	'	'	$727,465	$547,241	$46,305
Less: preferred share dividends	'	'	'	'	'	'	'	'	40,474	38,228	36,875
Less: loss on repurchase of preferred shares	'	'	'	'	'	'	'	'	3,081	14,009	0
Net income available to common shareholders	171,524	137,121	72,447	302,816	-18,551	223,407	168,152	121,997	683,910	495,004	9,430
Weighted average number of common shares outstanding - basic	'	'	'	'	'	'	'	'	113,636	122,148	122,499
Basic earnings per common share	$1.55	$1.23	$0.63	$2.59	($0.16)	$1.84	$1.36	$0.97	$6.02	$4.05	$0.08
Diluted earnings per common share	'	'	'	'	'	'	'	'	'	'	'
Net income available to common shareholders	$171,524	$137,121	$72,447	$302,816	($18,551)	$223,407	$168,152	$121,997	$683,910	$495,004	$9,430
Weighted average number of common shares outstanding - basic	'	'	'	'	'	'	'	'	113,636	122,148	122,499
Warrants	'	'	'	'	'	'	'	'	0	0	4,292
Stock compensation plans	'	'	'	'	'	'	'	'	1,692	1,506	1,331
Weighted average number of common shares outstanding - diluted	'	'	'	'	'	'	'	'	115,328	123,654	128,122
Diluted earnings per common share	$1.52	$1.21	$0.62	$2.55	($0.16)	$1.82	$1.35	$0.96	$5.93	$4	$0.07
Anti-dilutive shares excluded from the dilutive computation	'	'	'	'	'	'	'	'	250	614	1,134

SHAREHOLDERS_EQUITY_DETAILS

SHAREHOLDERS' EQUITY (DETAILS) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Class of Stock [Line Items]	'	'	'
Authorized share capital, common	800,000,000	800,000,000	'
Par value per share, common	$0.01	$0.01	'
Shares issued, balance at beginning of period	171,867,000	'	'
Total shares issued at end of period	174,134,000	171,867,000	'
Treasury shares, balance at beginning of period	-53,947,000	'	'
Total treasury shares at end of period	-64,649,000	-53,947,000	'
Total shares outstanding	109,485,000	117,920,000	'
Cash dividends declared per common share	$1.02	$0.97	$0.93
Common Stock [Member]	'	'	'
Class of Stock [Line Items]	'	'	'
Shares issued, balance at beginning of period	171,867,000	170,159,000	154,912,000
Shares issued	2,267,000	1,708,000	15,247,000
Total shares issued at end of period	174,134,000	171,867,000	170,159,000
Treasury shares, balance at beginning of period	-53,947,000	-44,571,000	-42,519,000
Shares repurchased	-10,830,000	-9,376,000	-2,052,000
Shares reissued from treasury	128,000	0	0
Total treasury shares at end of period	-64,649,000	-53,947,000	-44,571,000
Total shares outstanding	109,485,000	117,920,000	125,588,000

SHAREHOLDERS_EQUITY_DETAILS_2

SHAREHOLDERS' EQUITY (DETAILS 2) (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Class of Warrant or Right [Line Items]	'	'	'
Dividends paid	$118,426	$120,487	$206,455
Founders' Warrants [Member]	'	'	'
Class of Warrant or Right [Line Items]	'	'	'
Common shares issued to warrant holders	'	'	12,893,483
Warrants exercised	'	'	19,827,760
Dividends paid	'	'	$93,000

SHAREHOLDERS_EQUITY_DETAILS_3

SHAREHOLDERS' EQUITY (DETAILS 3) (Common Stock [Member], USD $)	0 Months Ended	12 Months Ended
	Dec. 09, 2013	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Treasury Shares [Line Items]	'	'	'	'
Value of share repurchase authorized by the Board of Directors during the period	$750,000,000	'	'	'
Total shares	'	10,830,000	9,376,000	2,052,000
Total cost	'	472,263,000	317,687,000	65,885,000
Average price per share	'	$43.61	$33.88	$32.11
In the Open Market [Member]	'	'	'	'
Treasury Shares [Line Items]	'	'	'	'
Total shares	'	7,362,000	6,057,000	1,609,000
Total cost	'	337,083,000	203,704,000	49,974,000
Average price per share	'	$45.79	$33.63	$31.07
From Employees [Member]	'	'	'	'
Treasury Shares [Line Items]	'	'	'	'
Total shares	'	468,000	319,000	443,000
Total cost	'	19,080,000	10,483,000	15,911,000
Average price per share	'	$40.75	$32.85	$35.92
From Founding Shareholder [Member]	'	'	'	'
Treasury Shares [Line Items]	'	'	'	'
Total shares	'	3,000,000	3,000,000	0
Total cost	'	$116,100,000	$103,500,000	$0
Average price per share	'	$38.70	$34.50	$0
From Founding Shareholder [Member] | Trident [Member]	'	'	'	'
Treasury Shares [Line Items]	'	'	'	'
Total shares	'	3,000,000	3,000,000	0

SHAREHOLDERS_EQUITY_DETAILS_4

SHAREHOLDERS' EQUITY (DETAILS 4) (USD $)

12 Months Ended

1 Months Ended

6 Months Ended

12 Months Ended

1 Months Ended

12 Months Ended

0 Months Ended

1 Months Ended

12 Months Ended

0 Months Ended

1 Months Ended

12 Months Ended

In Thousands, except Share data, unless otherwise specified

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Jun. 30, 2013

Dec. 17, 2012

Mar. 31, 2012

Oct. 31, 2005

Jun. 30, 2013

Jul. 15, 2013

Dec. 31, 2012

Dec. 31, 2011

Apr. 30, 2013

Nov. 30, 2005

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Jan. 15, 2013

Mar. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Mar. 03, 2014

31-May-13

Dec. 31, 2013

Series A 7.25% Preferred Shares [Member]

Series A 7.25% Preferred Shares [Member]

Series A 7.25% Preferred Shares [Member]

Series A 7.25% Preferred Shares [Member]

Series A 7.25% Preferred Shares [Member]

Series A 7.25% Preferred Shares [Member]

Series A 7.25% Preferred Shares [Member]

Series A 7.25% Preferred Shares [Member]

Series B 7.50% Preferred Shares [Member]

Series B 7.50% Preferred Shares [Member]

Series B 7.50% Preferred Shares [Member]

Series B 7.50% Preferred Shares [Member]

Series B 7.50% Preferred Shares [Member]

Series C 6.875% Preferred Shares [Member]

Series C 6.875% Preferred Shares [Member]

Series C 6.875% Preferred Shares [Member]

Series C 6.875% Preferred Shares [Member]

Series D 5.50% Preferred Shares [Member]

Series D 5.50% Preferred Shares [Member]

Series D 5.50% Preferred Shares [Member]

Class of Stock [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Preferred shares, aggregate liquidation value issued

'

'

'

'

'

'

$250,000

'

'

'

'

'

$250,000

'

'

'

'

$400,000

'

'

'

$225,000

'

Preferred shares, dividend rate

'

'

'

'

'

'

'

7.25%

'

'

'

'

'

7.50%

'

'

'

'

6.88%

'

'

'

5.50%

Preferred shares, aggregate liquidation preference repurchased

'

'

'

100,000

'

150,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Preferred shares, par value per share

'

'

'

$0.01

'

'

'

$0.01

'

'

'

'

'

$0.01

'

'

'

'

$0.01

'

'

'

$0.01

Preferred shares, liquidation preference per share

'

'

'

$25

'

'

'

$25

'

'

'

'

'

$100

'

'

'

'

$25

'

'

'

$25

Preferred shares, redemption price per share

'

'

'

'

'

'

'

'

'

'

'

'

'

$100

'

'

'

'

$25

'

'

'

$25

Preferred shares, floating dividend rate base

'

'

'

'

'

'

'

'

'

'

'

'

'

3.45%

'

'

'

'

'

'

'

'

'

Preferred shares, dividend declared per share

'

'

'

'

$0.45

'

'

$0.91

'

$1.81

$1.81

'

'

$7.50

$7.50

$7.50

'

'

$1.72

$1.41

'

'

$0.69

Preferred shares, dividends paid per share

'

'

'

'

'

'

'

'

$1.36

$1.81

$1.81

'

'

$7.50

$7.50

$7.50

$0.43

'

$1.72

$0.98

$0.34

'

$0.34

Preferred shares, number of shares repurchased

'

'

'

4,000,000

'

6,000,000

'

'

'

'

'

2,471,570

'

'

'

'

'

'

'

'

'

'

'

Loss on repurchase of preferred shares

3,081

14,009

0

3,000

'

5,000

'

'

'

'

'

9,000

'

'

'

'

'

'

'

'

'

'

'

Preferred shares, number of shares outstanding

'

'

'

'

'

'

'

'

'

'

'

'

'

28,430

'

'

'

'

'

'

'

'

'

Preferred shares, aggregate liquidation value outstanding

627,843

502,843

'

'

'

'

'

'

'

'

'

'

'

3,000

'

'

'

'

400,000

'

'

'

'

Preferred shares, purchase price per share

'

'

'

'

'

'

'

'

'

'

'

$102.81

'

'

'

'

'

'

'

'

'

'

'

Aggregate cash payment to acquire preferred shares

$100,000

$404,073

$0

'

'

'

'

'

'

'

'

$254,000

'

'

'

'

'

'

'

'

'

'

'

SHAREHOLDERS_EQUITY_DETAILS_5

SHAREHOLDERS' EQUITY (DETAILS 5) (Dividend Adjustment [Member], Common Stock [Member], USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2012
Dividend Adjustment [Member] | Common Stock [Member]	'
Out of period adjustment amount [Line Items]	'
Out of period adjustment amount	$31

NONCONTROLLING_INTEREST_DETAIL

NONCONTROLLING INTEREST (DETAILS) (USD $)	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2013
					Noncontrolling Interest [Member]
Noncontrolling Interest [Line Items]	'	'	'	'	'
Third party non-voting redeemable preferred share capital	'	'	'	'	$50,000,000
Cash and cash equivalents	$923,326,000	$759,817,000	$981,849,000	$929,515,000	$50,000,000

RETIREMENT_PLANS_DETAILS

RETIREMENT PLANS (DETAILS) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Compensation and Retirement Disclosure [Abstract]	'	'	'
Total pension expenses	$20	$20	$20

SHAREBASED_COMPENSATION_DETAIL

SHARE-BASED COMPENSATION (DETAILS)

12 Months Ended

1 Months Ended

1 Months Ended

12 Months Ended

1 Months Ended

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

31-May-12

31-May-09

31-May-07

Dec. 31, 2013

Feb. 10, 2014

Dec. 31, 2013

Feb. 10, 2014

Feb. 10, 2014

Restricted Stock And Restricted Stock Units [Member]

Restricted Stock And Restricted Stock Units [Member]

Restricted Stock And Restricted Stock Units [Member]

Restricted Stock And Restricted Stock Units [Member]

Restricted Stock And Restricted Stock Units [Member]

Stock Options [Member]

2007 Long-term Equity Compensation Plan [Member]

2007 Long-term Equity Compensation Plan [Member]

2007 Long-term Equity Compensation Plan [Member]

2007 Long-term Equity Compensation Plan [Member]

2007 Long-term Equity Compensation Plan [Member]

2007 Long-term Equity Compensation Plan [Member]

2007 Long-term Equity Compensation Plan [Member]

2007 Long-term Equity Compensation Plan [Member]

Performance [Member]

Service [Member]

Restricted Stock And Restricted Stock Units [Member]

Restricted Stock And Restricted Stock Units [Member]

Restricted Stock And Restricted Stock Units [Member]

Restricted Stock And Restricted Stock Units [Member]

Performance [Member]

Service [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Additional shares authorized for issuance under plan

'

'

'

'

'

'

6,000,000

4,000,000

5,000,000

'

'

'

'

'

Maximum number of shares to be issued under the plan

'

'

'

'

'

'

'

'

'

15,000,000

'

'

'

'

General award vesting period

'

'

'

'

'

'

'

'

'

'

'

'4 years

'

'

Annual award vesting percentage

'

'

'

'

'

'

'

'

'

'

'

25.00%

'

'

Period of time subsequent to a change in control during which plan allows for accelerated vesting of awards for certain terminations

'

'

'

'

'

'

'

'

'

'

'

'2 years

'

'

Number of restricted stock and restricted stock units granted

1,007,425

2,447,700

1,839,250

33,000

975,000

'

'

'

'

'

'

'

91,917

1,890,523

Number of restricted stock granted which will settle in cash

847,425

'

'

'

'

'

'

'

'

'

954,329

'

'

'

Number of awards available for grant under plan

'

'

'

'

'

'

'

'

'

6,310,845

'

'

'

'

Expiry date from date of grant

'

'

'

'

'

'10 years

'

'

'

'

'

'

'

'

SHAREBASED_COMPENSATION_DETAIL1

SHARE-BASED COMPENSATION (DETAILS 2) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Reconcilation of Beginning and Ending Balance of Nonvested Restricted Stock (including RSUs) [Line Items]	'	'	'
Accelerated and incremental share-based compensation expense related to senior leadership transitions	'	$20,000,000	'
Number of employees impacted by restricted stock award modifications during the period	'	1	'
Restricted Stock And Restricted Stock Units RSU [Member]	'	'	'
Reconcilation of Beginning and Ending Balance of Nonvested Restricted Stock (including RSUs) [Line Items]	'	'	'
Granted (number)	1,007,425	2,447,700	1,839,250
Weighted average grant date fair value - granted	$39.52	$32.20	$36.12
Share based compensation expense incurred	57,000,000	68,000,000	39,000,000
Tax benefit related to share-based compensation costs incurred	10,000,000	8,000,000	7,000,000
Number of restricted stock and restricted stock units granted which will settle in cash	847,425	'	'
Liability for cash-settled units	9,000,000	0	'
Fair value - vested during period	56,000,000	43,000,000	63,000,000
Unrecognized share-based compensation costs	$98,000,000	$89,000,000	'
Unrecognized share-based compensation costs, weighted average period expected to be recognized (years)	'2 years 164 days	'2 years 183 days	'
Restricted Stock And Restricted Stock Units RSU [Member] | Performance [Member]	'	'	'
Reconcilation of Beginning and Ending Balance of Nonvested Restricted Stock (including RSUs) [Line Items]	'	'	'
Nonvested restricted stock (number) - beginning of period	250,000	'	'
Granted (number)	33,000	'	'
Vested (number)	0	'	'
Forfeited (number)	0	'	'
Nonvested restricted stock (number) - end of period	283,000	'	'
Weighted average grant date fair value - beginning of period	$34.42	'	'
Weighted average grant date fair value - granted	$45.89	'	'
Weighted average grant date fair value - vested	$0	'	'
Weighted average grant date fair value - forfeited	$0	'	'
Weighted average grant date fair value - end of period	$35.74	'	'
Restricted Stock And Restricted Stock Units RSU [Member] | Service [Member]	'	'	'
Reconcilation of Beginning and Ending Balance of Nonvested Restricted Stock (including RSUs) [Line Items]	'	'	'
Nonvested restricted stock (number) - beginning of period	4,429,000	'	'
Granted (number)	975,000	'	'
Vested (number)	-1,754,000	'	'
Forfeited (number)	-220,000	'	'
Nonvested restricted stock (number) - end of period	3,430,000	'	'
Weighted average grant date fair value - beginning of period	$32.48	'	'
Weighted average grant date fair value - granted	$39.31	'	'
Weighted average grant date fair value - vested	$32.03	'	'
Weighted average grant date fair value - forfeited	$34.17	'	'
Weighted average grant date fair value - end of period	$34.72	'	'

SHAREBASED_COMPENSATION_DETAIL2

SHARE-BASED COMPENSATION (DETAILS 3) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Options outstanding [Roll Forward]	'	'
Options outstanding and exercisable, beginning of year	919,000	'
Granted	0	'
Exercised	-706,000	'
Expired	0	'
Options outstanding and exercisable, end of year	213,000	919,000
Options exercisable	213,000	919,000
Options outstanding, weighted average exercise price [Roll Forward]	'	'
Weighted average exercise price options outstanding, beginning of year	$28.74	'
Granted	$0	'
Exercised	$28.96	'
Expired	$0	'
Weighted average exercise price options outstanding, end of year	$27.98	$28.74
Weighted average exercise price, options exercisable	$27.98	$28.74
Weighted average remaining contractual term, options outstanding	'1 year 12 days	'
Weighted average remaining contractual term, options exercisable	'1 year 12 days	'
Aggregate intrinsic value, options outstanding	$4,180,000	'
Aggregate intrinsic value, options exercisable	4,180,000	'
Aggregate intrinsic value, options excerised	10,000,000	11,000,000
Proceeds received on exercise from options	$17,000,000	$3,000,000

RELATED_PARTY_TRANSACTIONS_DET

RELATED PARTY TRANSACTIONS (DETAILS) (USD $)	6 Months Ended			12 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2012	Jun. 30, 2012	Jun. 30, 2012	Dec. 31, 2011	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
	Blackstone Debt Advisors L.P. [Member]	Blackstone Alternative Asset Management L.P. [Member]	Blackstone Group [Member]	Blackstone Group [Member]	Stone Point Group [Member]	Stone Point Group [Member]	Stone Point Group [Member]
	security	security
Related Party Transaction [Line Items]	'	'	'	'	'	'	'
Number of CLO investments where related party is collateral manager	4	'	'	'	'	'	'
Number of hedge fund investments where related party is manager	'	2	'	'	'	'	'
Management fees paid to related party	'	'	$1	$2	$2	$2	$0

INCOME_TAXES_DETAILS

INCOME TAXES (DETAILS) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income tax expense [Line Items]	'	'	'
Total income tax expense	$7,002	$3,287	$15,233
Net current tax (liabilities) receivables	5,689	1,164	1,318
Net deferred tax assets	80,258	52,794	60,836
Net tax assets	85,947	53,958	62,154
United States [Member]	'	'	'
Income tax expense [Line Items]	'	'	'
Current income tax expense (benefit)	12,466	4,931	5,064
Deferred income tax expense (benefit)	-13,976	-10,749	1,379
Europe [Member]	'	'	'
Income tax expense [Line Items]	'	'	'
Current income tax expense (benefit)	9,039	8,566	9,598
Deferred income tax expense (benefit)	-526	713	-996
Other [Member]	'	'	'
Income tax expense [Line Items]	'	'	'
Current income tax expense (benefit)	0	-174	188
Deferred income tax expense (benefit)	($1)	$0	$0

INCOME_TAXES_DETAILS_2

INCOME TAXES (DETAILS 2) (USD $)	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
In Thousands, unless otherwise specified
Deferred tax assets	'	'	'
Discounting of loss reserves	$59,023	$61,534	'
Unearned premium	39,146	32,355	'
Operating loss carryforwards	20,316	20,685	'
Accruals not currently deductible	39,018	25,638	'
Other investment adjustments and impairments	7,859	8,790	'
Tax credits	11,886	7,945	'
Depreciation	2,410	3,858	'
Other deferred tax assets	2,906	2,185	'
Deferred tax assets before valulation allowance	182,564	162,990	'
Valuation allowance	-25,542	-24,574	'
Deferred tax assets net of valuation allowance	157,022	138,416	'
Deferred tax liabilities	'	'	'
Deferred acquisition costs	-37,226	-27,211	'
Net unrealized gains on investments	-23,200	-44,137	'
Amortization of intangible assets and goodwill	-10,059	-8,258	'
Accrued market discounts	-1,151	-1,323	'
Equalization reserves	-2,080	-1,957	'
Other deferred tax liabilities	-3,048	-2,736	'
Deferred tax liabilities	-76,764	-85,622	'
Net deferred tax assets	$80,258	$52,794	$60,836

INCOME_TAXES_DETAILS_3

INCOME TAXES (DETAILS 3) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Singapore [Member]	'	'
Income tax carryforwards [Line Items]	'	'
Operating Loss Carryforwards	$115	$117
Australia [Member]	'	'
Income tax carryforwards [Line Items]	'	'
Operating Loss Carryforwards	45	51
Europe [Member]	'	'
Income tax carryforwards [Line Items]	'	'
Foreign Tax Credit Carryforward	4	3
United States [Member] | Alternative Minimum Tax Carryforward [Member]	'	'
Income tax carryforwards [Line Items]	'	'
Foreign Tax Credit Carryforward	$7	$5

INCOME_TAXES_DETAILS_4

INCOME TAXES (DETAILS 4) (USD $)

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

In Thousands, unless otherwise specified

Income Tax Expense [Member]

Income Tax Expense [Member]

Income Tax Expense [Member]

Accumulated Other Comprehensive Income [Member]

Accumulated Other Comprehensive Income [Member]

Accumulated Other Comprehensive Income [Member]

Operating Loss Carryforwards [Member]

Operating Loss Carryforwards [Member]

Foreign Tax Credit [Member]

Foreign Tax Credit [Member]

Other Tax Carryforwards [Member]

Other Tax Carryforwards [Member]

Other Tax Carryforwards [Member]

Other Tax Carryforwards [Member]

Income Tax Expense [Member]

Income Tax Expense [Member]

Income Tax Expense [Member]

Income Tax Expense [Member]

Income Tax Expense [Member]

Income Tax Expense [Member]

Accumulated Other Comprehensive Income [Member]

Accumulated Other Comprehensive Income [Member]

Valuation allowance movement [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Valuation allowance, beginning of year

$25,542

$24,574

$27,070

$33,933

$30,623

($1,528)

($9,359)

($9,359)

'

'

'

'

'

'

'

'

Change in valuation allowance

'

'

'

'

'

'

'

'

-794

635

1,762

2,675

-7,831

0

7,831

0

Valuation allowance, end of year

$25,542

$24,574

$27,070

$33,933

$30,623

($1,528)

($9,359)

($9,359)

'

'

'

'

'

'

'

'

INCOME_TAXES_DETAILS_5

INCOME TAXES (DETAILS 5) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Reconciliation of effective tax rate (% of income before income taxes) [Line Items]	'	'	'
Expected tax rate	0.00%	0.00%	0.00%
Valuation allowance	-0.70%	0.60%	-15.50%
Net tax exempt income	-1.30%	-1.50%	-11.20%
Other	-0.40%	-0.30%	4.30%
Actual tax rate	1.00%	0.60%	24.80%
Income before income taxes - Bermuda (domestic)	$625,490	$485,613	$10,911
Income before income taxes - foreign	108,977	64,915	50,627
Income before income taxes	$734,467	$550,528	$61,538
United States [Member]	'	'	'
Reconciliation of effective tax rate (% of income before income taxes) [Line Items]	'	'	'
Foreign taxes at local expected rates	2.10%	0.40%	33.20%
Europe [Member]	'	'	'
Reconciliation of effective tax rate (% of income before income taxes) [Line Items]	'	'	'
Foreign taxes at local expected rates	1.00%	1.40%	10.70%
Other [Member]	'	'	'
Reconciliation of effective tax rate (% of income before income taxes) [Line Items]	'	'	'
Foreign taxes at local expected rates	0.30%	0.00%	3.30%

OTHER_COMPREHENSIVE_INCOME_LOS2

OTHER COMPREHENSIVE INCOME (LOSS) (DETAILS) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Before Tax Amount	'	'	'
Unrealized investment gains (losses) arising during the period	($169,614)	$378,040	$87,384
Adjustment for reclassification of net realized investment gains and OTTI losses recognized in net income	-67,156	-127,828	-121,248
Unrealized investment gains (losses) arising during the period, net of reclassification adjustment	-236,770	250,212	-33,864
Non-credit portion of OTTI losses	0	0	-585
Foreign currency translation adjustment	-21,414	510	-3,045
Net change in benefit plan assets and obligations recognized in equity and reclassification adjustment	0	1,718	92
Total other comprehensive income (loss)	-258,184	252,440	-37,402
Tax (Expense) Benefit	'	'	'
Unrealized investment gains (losses) arising during the period	7,782	-29,530	-13,087
Adjustment for reclassification of net realized investment gains and OTTI losses recognized in net income	5,605	11,550	1,700
Unrealized investment gains (losses) arising during the period, net of reclassification adjustment	13,387	-17,980	-11,387
Non-credit portion of OTTI losses	0	0	130
Foreign currency translation adjustment	0	0	0
Net change in benefit plan assets and obligations recognized in equity and reclassification adjustment	0	0	0
Total other comprehensive income (loss)	13,387	-17,980	-11,257
Net of Tax Amount	'	'	'
Unrealized investment gains (losses) arising during the period	-161,832	348,510	74,297
Adjustment for reclassification of net realized investment gains and OTTI losses recognized in net income	-61,551	-116,278	-119,548
Unrealized investment gains (losses) arising during the period, net of reclassification adjustment	-223,383	232,232	-45,251
Non-credit portion of OTTI losses	0	0	-455
Foreign currency translation adjustment	-21,414	510	-3,045
Net change in benefit plan assets and obligations recognized in equity and reclassification adjustment	0	1,718	92
Total other comprehensive income (loss), net of tax	($244,797)	$234,460	($48,659)

OTHER_COMPREHENSIVE_INCOME_LOS3

OTHER COMPREHENSIVE INCOME (LOSS) (DETAILS 2) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Reclassification out of accumulated comprehensive income into net income available to common shareholders [Line Items]	'	'	'
Other realized investment gains	$84,926	$151,703	$137,300
OTTI losses	-9,362	-24,234	-15,861
Income before income taxes	734,467	550,528	61,538
General and administrative expenses	-575,390	-560,981	-459,151
Tax benefit	-7,002	-3,287	-15,233
Net income	727,465	547,241	46,305
Unrealized appreciation on Available for Sale Securities [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]	'	'	'
Reclassification out of accumulated comprehensive income into net income available to common shareholders [Line Items]	'	'	'
Other realized investment gains	76,518	152,062	137,694
OTTI losses	-9,362	-24,234	-16,446
Income before income taxes	67,156	127,828	121,248
Tax benefit	-5,605	-11,550	-1,700
Net income	61,551	116,278	119,548
Supplemental Executive Retirement Plans (SERPs) [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]	'	'	'
Reclassification out of accumulated comprehensive income into net income available to common shareholders [Line Items]	'	'	'
General and administrative expenses	0	-1,718	-92
Tax benefit	0	0	0
Net income	$0	($1,718)	($92)

STATUTORY_FINANCIAL_INFORMATIO2

STATUTORY FINANCIAL INFORMATION (DETAILS) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Statutory Financial Information [Line Items]	'	'	'
Statutory net income	$766,000,000	$697,000,000	$99,000,000
Bermuda [Member]	'	'	'
Statutory Financial Information [Line Items]	'	'	'
Required statutory capital and surplus	1,996,794,000	2,048,329,000	'
Actual statutory capital and surplus	3,839,840,000	4,091,437,000	'
Minimum solvency margin amount	100,000,000	'	'
Minimum solvency margin percentage of net written premiums	50.00%	'	'
Minimum solvency margin percentage of net reserves	15.00%	'	'
Limit - prior year's total statutory capital surplus (Bermuda)	25.00%	'	'
Number of directors required to sign affadavit in order to pay dividend/distribution greater than 25% of prior year statutory capital and surplus	2	'	'
Maximum dividend/distribution payable without regulatory approval	1,000,000,000	'	'
Ireland [Member]	'	'	'
Statutory Financial Information [Line Items]	'	'	'
Required statutory capital and surplus	315,258,000	279,078,000	'
Actual statutory capital and surplus	906,932,000	904,237,000	'
Maximum dividend/distribution payable with regulatory approval	141,000,000	'	'
United States [Member]	'	'	'
Statutory Financial Information [Line Items]	'	'	'
Required statutory capital and surplus	385,651,000	358,674,000	'
Actual statutory capital and surplus	1,348,861,000	1,295,679,000	'
Maximum dividend/distribution payable without regulatory approval	$135,000,000	'	'
Maximum dividend limit - percentage of total statutory capital and surplus	10.00%	'	'

UNAUDITED_CONDENSED_QUARTERLY_2

UNAUDITED CONDENSED QUARTERLY FINANCIAL DATA (DETAILS) (USD $)	3 Months Ended								12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Quarterly Financial Information Disclosure [Abstract]	'	'	'	'	'	'	'	'	'	'	'
Net premiums earned	$941,911	$945,242	$945,873	$874,039	$856,049	$862,447	$850,603	$846,362	$3,707,065	$3,415,463	$3,314,961
Net investment income	113,863	103,429	83,112	108,908	86,847	103,638	74,449	116,023	409,312	380,957	362,430
Net realized investment gains (losses)	19,558	-4,708	16,235	44,478	31,771	50,803	30,405	14,491	75,564	127,469	121,439
Underwriting income (loss)	94,159	153,088	9,921	170,799	-74,291	154,999	119,739	62,689	'	'	'
Net income (loss) available to common shareholders	$171,524	$137,121	$72,447	$302,816	($18,551)	$223,407	$168,152	$121,997	$683,910	$495,004	$9,430
Basic earnings per common share	$1.55	$1.23	$0.63	$2.59	($0.16)	$1.84	$1.36	$0.97	$6.02	$4.05	$0.08
Diluted earnings per common share	$1.52	$1.21	$0.62	$2.55	($0.16)	$1.82	$1.35	$0.96	$5.93	$4	$0.07

SCHEDULE_II_CONDENSED_PARENT_C

SCHEDULE II - CONDENSED PARENT COMPANY BALANCE SHEETS (DETAILS) (USD $)	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
In Thousands, unless otherwise specified
Assets	'	'	'	'
Cash and cash equivalents	$923,326	$759,817	$981,849	$929,515
Other assets	273,385	215,369	'	'
Total assets	19,634,784	18,852,344	'	'
Liabilities	'	'	'	'
Senior notes	995,855	995,245	'	'
Other liabilities	248,822	228,623	'	'
Total liabilities	13,766,822	13,072,583	'	'
Shareholders' equity	'	'	'	'
Preferred shares	627,843	502,843	'	'
Common shares (2013: 174,134; 2012: 171,867 shares issued and 2013: 109,485; 2012: 117,920 shares outstanding)	2,174	2,146	'	'
Additional paid-in capital	2,240,125	2,179,034	'	'
Accumulated other comprehensive income	117,825	362,622	'	'
Retained earnings	5,062,706	4,497,789	'	'
Treasury shares, at cost (2013: 64,649; 2012: 53,947 shares)	-2,232,711	-1,764,673	'	'
Total shareholders' equity	5,817,962	5,779,761	'	'
Total liabilities and shareholders' equity	19,634,784	18,852,344	'	'
AXIS Capital Holdings Limited [Member]	'	'	'	'
Assets	'	'	'	'
Investment in subsidiaries on equity basis	6,581,368	6,571,607	'	'
Cash and cash equivalents	4,414	2,841	2,363	8,496
Other assets	3,179	2,706	'	'
Total assets	6,588,961	6,577,154	'	'
Liabilities	'	'	'	'
Intercompany payable	204,877	243,252	'	'
Senior notes	499,906	499,798	'	'
Dividends payable	47,959	37,370	'	'
Other liabilities	18,257	16,973	'	'
Total liabilities	770,999	797,393	'	'
Shareholders' equity	'	'	'	'
Preferred shares	627,843	502,843	'	'
Common shares (2013: 174,134; 2012: 171,867 shares issued and 2013: 109,485; 2012: 117,920 shares outstanding)	2,174	2,146	'	'
Additional paid-in capital	2,240,125	2,179,034	'	'
Accumulated other comprehensive income	117,825	362,622	'	'
Retained earnings	5,062,706	4,497,789	'	'
Treasury shares, at cost (2013: 64,649; 2012: 53,947 shares)	-2,232,711	-1,764,673	'	'
Total shareholders' equity	5,817,962	5,779,761	'	'
Total liabilities and shareholders' equity	$6,588,961	$6,577,154	'	'

SCHEDULE_II_CONDENSED_PARENT_C1

SCHEDULE II - CONDENSED PARENT COMPANY BALANCE SHEET PARENTHETICAL (DETAILS 2)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Condensed Financial Information of Parent Company [Line Items]	'	'
Common shares, shares issued	174,134	171,867
Common shares, shares outstanding	109,485	117,920
Treasury shares, shares	64,649	53,947
AXIS Capital Holdings Limited [Member]	'	'
Condensed Financial Information of Parent Company [Line Items]	'	'
Common shares, shares issued	174,134	171,867
Common shares, shares outstanding	109,485	117,920
Treasury shares, shares	64,649	53,947

SCHEDULE_II_CONDENSED_PARENT_C2

SCHEDULE II - CONDENSED PARENT COMPANY BALANCE SHEET NOTES (DETAILS 3) (USD $)	0 Months Ended		1 Months Ended				1 Months Ended
In Millions, unless otherwise specified	Nov. 15, 2004	Dec. 31, 2013	Mar. 23, 2010	Dec. 31, 2013	Dec. 31, 2013	Dec. 31, 2012	Nov. 30, 2004	Dec. 31, 2013	Dec. 31, 2013
	Senior Notes [Member]	Senior Notes [Member]	Senior Notes [Member]	Senior Notes [Member]	AXIS Capital Holdings Limited [Member]	AXIS Capital Holdings Limited [Member]	AXIS Capital Holdings Limited [Member]	AXIS Capital Holdings Limited [Member]	AXIS Capital Holdings Limited [Member]
	2004 AXIS Capital Holdings Limited Senior Notes [Member]	2004 AXIS Capital Holdings Limited Senior Notes [Member]	2010 AXIS Capital Finance LLC Senior Notes [Member]	2010 AXIS Capital Finance LLC Senior Notes [Member]	Weather Related Derivative [Member]	Weather Related Derivative [Member]	Senior Notes [Member]	Senior Notes [Member]	Senior Notes [Member]
					Full and Unconditional Guarantee of Debt [Member]	Full and Unconditional Guarantee of Debt [Member]	2004 AXIS Capital Holdings Limited Senior Notes [Member]	2004 AXIS Capital Holdings Limited Senior Notes [Member]	2010 AXIS Capital Finance LLC Senior Notes [Member]
									Full and Unconditional Guarantee of Debt [Member]
Condensed Financial Information of Parent Company [Line Items]	'	'	'	'	'	'	'	'	'
Face amount	'	$500	'	$500	'	'	'	$500	'
Interest rate	'	5.75%	'	5.88%	'	'	'	5.75%	5.88%
Issue price (percentage of face amount)	99.79%	'	99.62%	'	'	'	99.79%	'	'
Net proceeds on issuance	496	'	495	'	'	'	496	'	'
Percentage ownership in subsidiary	'	'	'	100.00%	'	'	'	'	100.00%
Principal amount guaranteed	'	'	'	'	'	'	'	'	500
Guarantor obligations, current carrying value	'	'	'	'	$28	$0	'	'	'

SCHEDULE_II_CONDENSED_PARENT_C3

SCHEDULE II - CONDENSED PARENT COMPANY STATEMENTS OF OPERATIONS (DETAILS 4) (USD $)	3 Months Ended								12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Revenues	'	'	'	'	'	'	'	'	'	'	'
Total revenues	'	'	'	'	'	'	'	'	$4,196,365	$3,926,565	$3,801,226
Expenses	'	'	'	'	'	'	'	'	'	'	'
Interest expense and financing costs	'	'	'	'	'	'	'	'	61,979	61,863	62,598
Net income	'	'	'	'	'	'	'	'	727,465	547,241	46,305
Preferred share dividends	'	'	'	'	'	'	'	'	40,474	38,228	36,875
Loss on repurchase of preferred shares	'	'	'	'	'	'	'	'	3,081	14,009	0
Net income available to common shareholders	171,524	137,121	72,447	302,816	-18,551	223,407	168,152	121,997	683,910	495,004	9,430
Comprehensive income (loss)	'	'	'	'	'	'	'	'	482,668	781,701	-2,354
AXIS Capital Holdings Limited [Member]	'	'	'	'	'	'	'	'	'	'	'
Revenues	'	'	'	'	'	'	'	'	'	'	'
Net investment income	'	'	'	'	'	'	'	'	5	25	1
Total revenues	'	'	'	'	'	'	'	'	5	25	1
Expenses	'	'	'	'	'	'	'	'	'	'	'
General and administrative expenses	'	'	'	'	'	'	'	'	40,565	62,293	36,248
Interest expense and financing costs	'	'	'	'	'	'	'	'	29,201	29,201	29,201
Total expenses	'	'	'	'	'	'	'	'	69,766	91,494	65,449
Loss before equity in net earnings of subsidiaries	'	'	'	'	'	'	'	'	-69,761	-91,469	-65,448
Equity in net earnings of subsidiaries	'	'	'	'	'	'	'	'	797,226	638,710	111,753
Net income	'	'	'	'	'	'	'	'	727,465	547,241	46,305
Preferred share dividends	'	'	'	'	'	'	'	'	40,474	38,228	36,875
Loss on repurchase of preferred shares	'	'	'	'	'	'	'	'	3,081	14,009	0
Net income available to common shareholders	'	'	'	'	'	'	'	'	683,910	495,004	9,430
Comprehensive income (loss)	'	'	'	'	'	'	'	'	$482,668	$781,701	($2,354)

SCHEDULE_II_CONDENSED_PARENT_C4

SCHEDULE II - CONDENSED PARENT COMPANY STATEMENTS OF CASH FLOWS (DETAILS 5) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Cash flows from operating activities:	'	'	'
Net income	$727,465	$547,241	$46,305
Adjustments to reconcile net income to net cash provided by operating activities:	'	'	'
Other items	789	-85,442	77,782
Net cash provided by operating activities	1,096,968	1,120,617	1,190,142
Cash flows from investing activities:	'	'	'
Net cash from investing activities	-489,287	-862,381	-832,718
Cash flows from financing activities:	'	'	'
Net proceeds from issuance of preferred shares	218,449	393,544	0
Repurchase of preferred shares	-100,000	-404,073	0
Repurchase of common shares	-472,263	-317,687	-65,885
Dividends paid - common shares	-118,426	-120,487	-206,455
Dividends paid - preferred shares	-39,193	-38,228	-36,875
Proceeds from issuance of common shares	20,339	5,120	6,735
Net cash used in financing activities	-441,094	-481,811	-302,480
Increase (decrease) in cash and cash equivalents	163,509	-222,032	52,334
Cash and cash equivalents - beginning of period	759,817	981,849	929,515
Cash and cash equivalents - end of period	923,326	759,817	981,849
Supplemental disclosures of cash flow information	'	'	'
Interest paid	58,125	58,125	58,125
AXIS Capital Holdings Limited [Member]	'	'	'
Cash flows from operating activities:	'	'	'
Net income	727,465	547,241	46,305
Adjustments to reconcile net income to net cash provided by operating activities:	'	'	'
Equity in net earnings of subsidiaries	-797,226	-638,710	-111,753
Change in intercompany payable	-38,375	-7,667	-44,503
Dividends received from subsidiaries	566,000	525,000	255,000
Other items	34,803	56,425	21,298
Net cash provided by operating activities	492,667	482,289	166,347
Cash flows from investing activities:	'	'	'
Capital repaid from subsidiary	0	0	130,000
Net cash from investing activities	0	0	130,000
Cash flows from financing activities:	'	'	'
Net proceeds from issuance of preferred shares	218,449	393,544	0
Repurchase of preferred shares	-100,000	-404,073	0
Repurchase of common shares	-472,263	-317,687	-65,885
Dividends paid - common shares	-118,426	-120,487	-206,455
Dividends paid - preferred shares	-39,193	-38,228	-36,875
Proceeds from issuance of common shares	20,339	5,120	6,735
Net cash used in financing activities	-491,094	-481,811	-302,480
Increase (decrease) in cash and cash equivalents	1,573	478	-6,133
Cash and cash equivalents - beginning of period	2,841	2,363	8,496
Cash and cash equivalents - end of period	4,414	2,841	2,363
Supplemental disclosures of cash flow information	'	'	'
Interest paid	$28,750	$28,750	$28,750

SCHEDULE_III_SUPPLEMENTARY_INS1

SCHEDULE III - SUPPLEMENTARY INSURANCE INFORMATION (DETAILS) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Supplementary Insurance Information [Line Items]	'	'	'
Deferred Acquisition Costs	$456,122	$389,248	$407,527
Reserve for Losses and Loss Expenses	9,582,140	9,058,731	8,425,045
Unearned Premiums	2,683,849	2,454,692	2,454,462
Net Premiums Earned	3,707,065	3,415,463	3,314,961
Net Investment Income	409,312	380,957	362,430
Losses and Loss Expenses	2,134,195	2,096,028	2,675,052
Amortization of Deferred Acquisition Costs	664,191	627,653	587,469
Other Operating Expenses	575,390	560,981	459,151
Net Premiums Written	3,928,200	3,337,456	3,419,434
Insurance [Member]	'	'	'
Supplementary Insurance Information [Line Items]	'	'	'
Deferred Acquisition Costs	150,109	128,311	142,743
Reserve for Losses and Loss Expenses	4,873,184	4,492,553	4,081,741
Unearned Premiums	1,548,653	1,456,318	1,412,699
Net Premiums Earned	1,722,762	1,558,058	1,429,687
Net Investment Income	0	0	0
Losses and Loss Expenses	1,050,402	953,564	919,319
Amortization of Deferred Acquisition Costs	242,363	226,859	199,583
Other Operating Expenses	347,684	314,834	278,147
Net Premiums Written	1,813,538	1,522,245	1,466,134
Reinsurance [Member]	'	'	'
Supplementary Insurance Information [Line Items]	'	'	'
Deferred Acquisition Costs	306,013	260,937	264,784
Reserve for Losses and Loss Expenses	4,708,956	4,566,178	4,343,304
Unearned Premiums	1,135,196	998,374	1,041,763
Net Premiums Earned	1,984,303	1,857,405	1,885,274
Net Investment Income	0	0	0
Losses and Loss Expenses	1,083,793	1,142,464	1,755,733
Amortization of Deferred Acquisition Costs	421,828	400,794	387,886
Other Operating Expenses	137,450	116,487	103,915
Net Premiums Written	2,114,662	1,815,211	1,953,300
Corporate [Member]	'	'	'
Supplementary Insurance Information [Line Items]	'	'	'
Deferred Acquisition Costs	0	0	0
Reserve for Losses and Loss Expenses	0	0	0
Unearned Premiums	0	0	0
Net Premiums Earned	0	0	0
Net Investment Income	409,312	380,957	362,430
Losses and Loss Expenses	0	0	0
Amortization of Deferred Acquisition Costs	0	0	0
Other Operating Expenses	90,256	129,660	77,089
Net Premiums Written	$0	$0	$0

SCHEDULE_IV_SUPPLEMENTARY_REIN1

SCHEDULE IV - SUPPLEMENTARY REINSURANCE INFORMATION (DETAILS) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Supplemental Schedule of Reinsurance Premiums for Insurance Companies [Abstract]	'	'	'
Direct Gross Premium	$1,974,915	$1,805,887	$1,696,600
Ceded To Other Companies	768,841	802,187	676,719
Assumed from Other Companies	2,722,126	2,333,756	2,399,553
Net	$3,928,200	$3,337,456	$3,419,434
Percentage of Amount Assumed to Net	69.30%	69.90%	70.20%