XML 105 R35.htm IDEA: XBRL DOCUMENT
v2.4.0.6

SCHEDULE VI SUPPLEMENTAL INFORMATION FOR PROPERTY AND CASUALTY INSURANCE UNDERWRITERS | 12 Months Ended
--- | ---
Dec. 31, 2012
Supplemental Information for Property, Casualty Insurance Underwriters [Abstract] |
SCHEDULE VI SUPPLEMENTAL INFORMATION FOR PROPERTY AND CASUALTY INSURANCE UNDERWRITERS | WHITE MOUNTAINS INSURANCE GROUP, LTD. SUPPLEMENTAL INFORMATION FOR PROPERTY AND CASUALTY INSURANCE UNDERWRITERS (Millions)
Column A |  | Column B |  | Column C |  | Column D |  | Column E |  | Column F |  | Column G |  | Column H |  | Column I |  | Column J |  | Column K
|  | Deferred acquisition costs |  | Reserves for Unpaid Claims and Claims Adjustment Expenses |  | Discount, if any, deducted in Column C |  | Unearned Premiums |  | Earned Premiums |  | Net investment income |  | Claims and Claims Adjustment Expenses Incurred Related to |  | Amortization of deferred policy acquisition costs |  | Paid Claims and Claims Adjustment Expenses |  | Premiums written
Affiliation with registrant |  |  |  |  |  |  |  | (1) Current Year |  | (2) Prior Year |  |  |
OneBeacon: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
2012 |  | $ | 123.9 |  |  | $ | 1,000.0 |  |  | $ | 4.6 |  | (1) | $ | 573.8 |  |  | $ | 1,132.0 |  |  | $ | 53.6 |  |  | $ | 657.4 |  |  | $ | (7.4 | ) |  | $ | 249.4 |  |  | $ | 565.1 |  |  | $ | 1,179.2 |
2011 |  | 123.5 |  |  | 3,358.6 |  |  | 271.6 |  | (1) | 528.0 |  |  | 1,012.2 |  |  | 71.4 |  |  | 578.1 |  |  | (29.8 | ) |  | 221.2 |  |  | 523.2 |  |  | 1,062.7 |
2010 |  | 114.5 |  |  | 3,295.5 |  |  | 295.9 |  | (1) | 627.5 |  |  | 1,181.1 |  |  | 96.6 |  |  | 721.6 |  |  | (36.0 | ) |  | 252.1 |  |  | 654.8 |  |  | 1,167.7 |
Sirius Group: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
2012 |  | $ | 71.4 |  |  | $ | 2,168.9 |  |  | $ | 2.4 |  | (2) | $ | 350.2 |  |  | $ | 931.6 |  |  | $ | 65.0 |  |  | $ | 578.4 |  |  | $ | (34.5 | ) |  | $ | 180.8 |  |  | $ | 741.2 |  |  | $ | 947.7 |
2011 |  | 63.5 |  |  | 2,343.7 |  |  | 12.8 |  | (2) | 319.0 |  |  | 912.3 |  |  | 89.9 |  |  | 672.9 |  |  | (46.9 | ) |  | 181.0 |  |  | 642.0 |  |  | 915.7 |
2010 |  | 61.6 |  |  | 2,441.3 |  |  | 21.1 |  | (2) | 311.2 |  |  | 847.9 |  |  | 90.5 |  |  | 588.1 |  |  | (57.1 | ) |  | 167.5 |  |  | 437.0 |  |  | 865.8 |
(1) | The amounts shown represent OneBeacon’s discount on its long-term workers compensation loss and LAE reserves, as such liabilities constitute unpaid but settled claims under which the payment pattern and ultimate costs are fixed and determinable on an individual basis. OneBeacon discounts these reserves using a discount rate which is determined based on the facts and circumstances applicable at the time the claims are settled (3.5%, 4.5% and 5.0% at December 31, 2012, 2011 and 2010). Also the amounts shown include unamortized fair value adjustments to reserves for unpaid claims and claims adjustment expenses made in purchase accounting as a result of White Mountains’ purchase of OneBeacon for the years ended December 31, 2012, 2011 and 2010.
(2) | The amount shown represents unamortized fair value adjustments to reserves for unpaid claims and claims adjustment expenses made in purchase accounting as a result of White Mountains’ purchase of Sirius International during 2004.

X
- Definition The entire disclosure for the supplemental schedule of information for an entity who has a consolidated property-casualty insurance underwriter, unconsolidated property-casualty subsidiary or fifty percent-or-less owned property-casualty equity investee. + References Reference 1: 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 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 18 -Article 12 + Details
Name: | us-gaap_ScheduleOfSupplementalInformationForPropertyCasualtyInsuranceUnderwritersTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

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