XML 19 R33.htm IDEA: XBRL DOCUMENT
v2.4.0.6

Investments in Unconsolidated Affiliates (Tables) | 3 Months Ended
--- | ---
Mar. 31, 2013
Equity Method Investments and Joint Ventures [Abstract] |
Investments in and Advances to Affiliates | White Mountains’ investments in unconsolidated affiliates represent investments in other companies in which White Mountains has a significant voting and economic interest but does not control the entity.
Millions |  | March 31, 2013 |  | December 31, 2012
Symetra common shares |  | $ | 296.8 |  |  | $ | 288.4 |
Unrealized gains from Symetra's fixed maturity portfolio |  | 54.1 |  |  | 62.8 |
Carrying value of Symetra common shares |  | 350.9 |  |  | 351.2 |
Symetra warrants |  | 26.6 |  |  | 30.3 |
Total investment in Symetra |  | 377.5 |  |  | 381.5 |
Hamer |  | 3.8 |  |  | 4.0 |
Bri-Mar |  | 1.8 |  |  | 1.9 |
Pentelia Capital Management |  | .5 |  |  | .5 |
Total investments in unconsolidated affiliates |  | $ | 383.6 |  |  | $ | 387.9 |
Schedule of Changes in Investments in Unconsolidated Affiliates | The following table summarizes amounts recorded by White Mountains relating to its investment in Symetra for the three months ended March 31, 2013 and 2012:
|  | Three Months Ended |  | Three Months Ended
|  | March 31, 2013 |  | March 31, 2012
Millions |  | Common Shares |  | Warrants |  | Total |  | Common Shares |  | Warrants |  | Total
Carrying value of investment in Symetra as of January 1 |  | $ | 351.2 |  |  | $ | 30.3 |  |  | $ | 381.5 |  |  | $ | 261.0 |  |  | $ | 12.6 |  |  | $ | 273.6 |
Equity in earnings (1)(2) |  | 9.8 |  |  | — |  |  | 9.8 |  |  | 10.9 |  |  | — |  |  | 10.9 |
Equity in net unrealized gains from Symetra’s fixed maturity portfolio(3) |  | (8.7 | ) |  | — |  |  | (8.7 | ) |  | (1.2 | ) |  | — |  |  | (1.2 | )
Dividends received |  | (1.4 | ) |  | — |  |  | (1.4 | ) |  | (1.2 | ) |  | — |  |  | (1.2 | )
(Decrease) increase in value of warrants |  | — |  |  | (3.7 | ) |  | (3.7 | ) |  | — |  |  | 11.1 |  |  | 11.1 |
Carrying value of investment in Symetra as March 31 (4)(5) |  | $ | 350.9 |  |  | $ | 26.6 |  |  | $ | 377.5 |  |  | $ | 269.5 |  |  | $ | 23.7 |  |  | $ | 293.2 |
(1) Equity in earnings excludes tax expense of $0.8 and $0.7. (2) Equity in earnings includes $0.7 and $1.1 increase relating to the pre-tax amortization of Symetra common share impairment from March 31, 2013 and 2012. (3) Net unrealized gains includes $2.7 and $3.2 increase relating to the pre-tax amortization of Symetra common share impairment from March 31, 2013 and 2012. (4) Includes White Mountains’ equity in net unrealized gains from Symetra’s fixed maturity portfolio of $(8.7) and $(1.2) as of March 31, 2013 and 2012, which exclude tax benefit of $0.7 and $0.0. (5) The aggregate value of White Mountains’ investment in common shares of Symetra was $233.3 based upon the quoted market price of $13.41 per share at March 31, 2013.

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

X
- Definition Tabular disclosure of investments in and advances to affiliates. Does not include the tabular disclosure of the disaggregation of investments in and advances to affiliates across legal entities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 946 -SubTopic 320 -Section S99 -Paragraph 6 -Subparagraph (SX 210.12-14) -URI http://asc.fasb.org/extlink&oid=6955306&loc=d3e611322-123010 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 14 -Article 12 + Details
Name: | us-gaap_InvestmentsInAndAdvancesToAffiliatesTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Disclosure of changes in the investment in unconsolidated affiliates. + References No definition available. + Details
Name: | wtm_ScheduleOfChangesInInvestmentsInUnconsolidatedAffiliatesTableTextBlock
Namespace Prefix: | wtm_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration