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SCHEDULE VI SUPPLEMENTAL INFORMATION FOR PROPERTY AND CASUALTY INSURANCE UNDERWRITERS (Details) (USD $) In Millions, unless otherwise specified | 12 Months Ended |  |
--- | --- | --- | ---
Dec. 31, 2011 OneBeacon | Dec. 31, 2010 OneBeacon | Dec. 31, 2009 OneBeacon | Dec. 31, 2011 Sirius | Dec. 31, 2010 Sirius | Dec. 31, 2009 Sirius | Dec. 31, 2009 50%-or-less owned property and casualty investees - Delos | Dec. 31, 2011 50%-or-less owned property and casualty investees - Delos | Aug. 03, 2006 50%-or-less owned property and casualty investees - Delos
SUPPLEMENTAL INFORMATION FOR PROPERTY AND CASUALTY INSURANCE UNDERWRITERS |  |  |  |  |  |  |  |  |
Deferred acquisition costs | $ 123.5 | $ 114.5 | $ 215.0 | $ 63.5 | $ 61.6 | $ 57.2 | $ 3.9 |  |
Reserves for Unpaid Claims and Claims Adjustment Expenses | 3,358.6 | 3,295.5 | 3,934.8 | 2,343.7 | 2,441.3 | 2,444.4 | 73.3 |  |
Discount, if any, deducted in Column C | 271.6 | 295.9 | 317.5 | 12.8 | 21.1 | 29.5 |  |  |
Unearned Premiums | 528.0 | 627.5 | 1,018.3 | 319.0 | 311.2 | 287.5 | 26.1 |  |
Earned Premiums | 1,015.5 | 1,487.7 | 1,959.5 | 912.3 | 847.9 | 858.8 | 33.3 |  |
Net investment income | 71.4 | 96.6 | 125.5 | 89.9 | 90.5 | 107.7 | 1.7 |  |
Current Year | 583.8 | 981.4 | 1,205.3 | 672.9 | 588.1 | 449.1 | 24.3 |  |
Prior Year | (2.9) | (51.2) | (83.4) | (46.9) | (57.1) | (30.4) |  |  |
Amortization of deferred policy acquisition costs | 219.0 | 320.7 | 398.3 | 181.0 | 167.5 | 170.9 |  |  |
Paid Claims and Claims Adjustment Expenses | 714.8 | 1,038.8 | 1,176.1 | 642.0 | 437.0 | 772.9 | 18.2 |  |
Premiums written | $ 1,062.9 | $ 1,236.3 | $ 1,906.7 | $ 915.7 | $ 865.8 | $ 806.8 | $ 31.7 |  |
Rate at which reserves are discounted (as a percent) | 4.50% | 5.00% | 5.30% |  |  |  |  |  |
Ownership interest in property and casualty insurance affiliates (as a percent) |  |  |  |  |  |  |  | 50.00% | 18.00%

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- Definition Amount of amortization expense on deferred policy acquisition cost. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 18 -Article 12 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 235 -Section S99 -Paragraph 3 -Subparagraph (SX 210.12-18) -URI http://asc.fasb.org/extlink&oid=6588446&loc=d3e575016-122915 + Details
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- Definition Amount of insurance benefit, claims, loss and settlement expenses paid to the policyholders during the current accounting period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 18 -Article 12 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 235 -Section S99 -Paragraph 3 -Subparagraph (SX 210.12-18) -URI http://asc.fasb.org/extlink&oid=6588446&loc=d3e575016-122915 + Details
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- Definition Amount of deferred policy acquisition cost related to property-casualty insurance policy written. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 18 -Article 12 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 235 -Section S99 -Paragraph 3 -Subparagraph (SX 210.12-18) -URI http://asc.fasb.org/extlink&oid=6588446&loc=d3e575016-122915 + Details
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- Definition The amount of discount that may be deducted from the reserve for unpaid claims and claims adjustment expense. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 18 -Article 12 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 235 -Section S99 -Paragraph 3 -Subparagraph (SX 210.12-18) -URI http://asc.fasb.org/extlink&oid=6588446&loc=d3e575016-122915 + Details
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- Definition Amount of property-casualty insurance premium revenue earned on insurance policies. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 18 -Article 12 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 235 -Section S99 -Paragraph 3 -Subparagraph (SX 210.12-18) -URI http://asc.fasb.org/extlink&oid=6588446&loc=d3e575016-122915 + Details
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- Definition The rate at which the discount was computed for each business segment reported. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 18 -Article 12 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 235 -Section S99 -Paragraph 3 -Subparagraph (SX 210.12-18) -URI http://asc.fasb.org/extlink&oid=6588446&loc=d3e575016-122915 + Details
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- Definition Amount of net investment income earned by property-casualty insurance underwriter. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 18 -Article 12 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 235 -Section S99 -Paragraph 3 -Subparagraph (SX 210.12-18) -URI http://asc.fasb.org/extlink&oid=6588446&loc=d3e575016-122915 + Details
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- Definition Payments of claims and claims adjustment expenses during the period of a property-casualty insurance entity. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 18 -Article 12 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 235 -Section S99 -Paragraph 3 -Subparagraph (SX 210.12-18) -URI http://asc.fasb.org/extlink&oid=6588446&loc=d3e575016-122915 + Details
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- Definition Amount of actual premium written by property-casualty insurance underwriter. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 18 -Article 12 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 235 -Section S99 -Paragraph 3 -Subparagraph (SX 210.12-18) -URI http://asc.fasb.org/extlink&oid=6588446&loc=d3e575016-122915 + Details
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- Definition Amount of insurance benefit, claims, loss and settlement expenses paid to the policyholders during the prior accounting period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 18 -Article 12 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 235 -Section S99 -Paragraph 3 -Subparagraph (SX 210.12-18) -URI http://asc.fasb.org/extlink&oid=6588446&loc=d3e575016-122915 + Details
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- Definition The amount of reserve, policy claim payable and loss expense incurred by property-casualty insurance underwriter. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 18 -Article 12 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 235 -Section S99 -Paragraph 3 -Subparagraph (SX 210.12-18) -URI http://asc.fasb.org/extlink&oid=6588446&loc=d3e575016-122915 + Details
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- Definition Amount of property-casualty insurance premium revenue not yet earned on insurance policies. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 18 -Article 12 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 235 -Section S99 -Paragraph 3 -Subparagraph (SX 210.12-18) -URI http://asc.fasb.org/extlink&oid=6588446&loc=d3e575016-122915 + Details
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