Reserve For Losses, LAE And Future Policy Benefit Reserve (Narrative) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2011 years	Dec. 31, 2010	Dec. 31, 2009
Prior years' reserves	$ 3,691	$ (30,866)	$ 128,838
Increase (decrease) in insurance business and non-US reinsurance business	113,833	(140,760)	59,019
Increase in insurance and reinsurance business	110,142	109,894	69,819
Reinsurance receivables	580,339	684,718
Retrocession percent	5.00%
Contracts of insurance and reinsurance received claims during the past three years	20
Case reserves reported by ceding companies	145,571
Additional case reserves established by the Company on assumed reinsurance claims	102,934
Case reserves established by the Company on direct excess insurance claims	40,555
IBNR reserves	210,851
Gross asbestos loss reserves	479,729
Gross asbestos loss reserves, percent	96.00%
Assumed business	382,334
Direct business	97,395
C.V. Starr [Member]
Reinsurance receivables	213,601
Reinsurance receivables, percent	36.80%
Transatlantic Reinsurance Company [Member]
Reinsurance receivables	66,268
Reinsurance receivables, percent	11.40%
Munich Reinsurance Company [Member]
Reinsurance receivables	39,852
Reinsurance receivables, percent	6.90%
Berkley Insurance Company [Member]
Reinsurance receivables	$ 56,895
Reinsurance receivables, percent	9.80%

Assumed liability for unpaid claims and claims adjustment expense for direct business.

No definition available.

Name:	re_AssumedLiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseForDirectBusiness
Namespace Prefix:	re_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Expiry of asbestos and environmental claims receivables years.

+ References

No definition available.

+ Details

Name:	re_ExpiryOfAsbestosAndEnvironmentalClaimsReceivablesYears
Namespace Prefix:	re_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Liability for asbestos and environmental claims gross percent.

+ References

No definition available.

+ Details

Name:	re_LiabilityForAsbestosAndEnvironmentalClaimsGrossPercent
Namespace Prefix:	re_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Reinsurance receivables percent.

+ References

No definition available.

+ Details

Name:	re_ReinsuranceReceivablesPercent
Namespace Prefix:	re_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Retrocession percent.

+ References

No definition available.

+ Details

Name:	re_RetrocessionPercent
Namespace Prefix:	re_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Liability as of the balance sheet date for the estimated ultimate cost of settling claims and claim adjustment expense relating to insured events that have occurred on or before the balance sheet date for those liabilities owed to another party as a result of assuming another insurer's primary obligation.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 40

-Section 50

-Paragraph 3

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=6482485&loc=d3e14764-158437

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 5

-Paragraph 9

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Statement of Position (SOP)

-Number 94-5

-Paragraph 11

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 113

-Paragraph 15, 16

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

Name:	us-gaap_AssumedLiabilityForUnpaidClaimsAndClaimsAdjustmentExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The monetary Increase or Decrease in the reporting period in the reserve for costs of settling insured claims and costs incurred in the claims settlement process for the specified cause.

+ References

+ Details

Name:	us-gaap_CausesOfIncreaseDecreaseInLiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The increase (decrease) during the reporting period in asbestos and environmental claims reserve, before estimated recoveries from reinsurers.

+ References

+ Details

Name:	us-gaap_LiabilityForAsbestosAndEnvironmentalClaimsGrossPeriodIncreaseDecrease
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	duration

- Definition

Estimated costs as of the balance sheet date of settling insured claims and costs incurred in the claims settlement process for claims that have not yet been submitted to the insurance company for reimbursement.

+ References

+ Details

Name:	us-gaap_LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseIncurredButNotReportedIBNRClaimsAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of provision in the period for claims incurred in prior reporting periods and related claims settlement costs.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Statement of Position (SOP)

-Number 94-5

-Paragraph 11

-Subparagraph b

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Financial Reporting Release (FRR)

-Number 403

-Paragraph 04

-Subparagraph b

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 40

-Section 50

-Paragraph 3

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6482485&loc=d3e14764-158437

+ Details

Name:	us-gaap_LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseIncurredClaimsPriorYears
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The amount of the other adjustment made to the claims reserves during the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Statement of Position (SOP)

-Number 94-5

-Paragraph 11

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Statement of Position (SOP)

-Number 94-5

-Paragraph 16, 17, 18, 19

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 40

-Section 50

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=6482485&loc=d3e14764-158437

+ Details

Name:	us-gaap_LiabilityForUnpaidClaimsAndClaimsAdjustmentExpensePeriodIncreaseDecrease
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	duration

- Definition

The accrued obligation as of the balance sheet date which represents the cost of settling insured claims and insured claims relating to insured events that have occurred but have not yet been reported to the insurer or reinsurer as of the date of the financial statements.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 40

-Section S99

-Paragraph 1

-Subparagraph (SAB TOPIC 5.W)

-URI http://asc.fasb.org/extlink&oid=6483420&loc=d3e570705-122907

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 5

-Paragraph 9

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 5

-Section W

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 40

-Section 50

-Paragraph 3

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=6482485&loc=d3e14764-158437

+ Details

Name:	us-gaap_LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseReportedAndIncurredButNotReportedIBNRClaims
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Costs of settling insured claims and costs incurred in the claims settlement process for the specified year specifically for claims that have already been submitted to the insurance company for reimbursement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Statement of Position (SOP)

-Number 94-5

-Paragraph 10, 11

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 40

-Section 50

-Paragraph 3

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=6482485&loc=d3e14764-158437

+ Details

Name:	us-gaap_LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseReportedClaimsAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The amount of the provision for the period for claims and benefits incurred on contract risks assumed from other (ceding) insurers under reinsurance arrangements.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 113

-Paragraph 27, 113

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

Name:	us-gaap_ReinsuranceEffectOnClaimsAndBenefitsIncurredAmountAssumed
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Receivables currently due from reinsurers for ceded claims paid.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 310

-Section 45

-Paragraph 5

-URI http://asc.fasb.org/extlink&oid=6485522&loc=d3e21409-158489

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-03.6)

-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Article 7

-Section 03

-Paragraph 6

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 605

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6486672&loc=d3e27261-158547

-Subparagraph (a)(2)

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 113

-Paragraph 14, 15

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 310

-Section 45

-Paragraph 6

-URI http://asc.fasb.org/extlink&oid=6485522&loc=d3e21412-158489

+ Details

Name:	us-gaap_ReinsuranceReceivablesPaidLossesRecoverable
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant