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Subsequent Event (Notes) | 12 Months Ended
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Dec. 31, 2012
Subsequent Events [Abstract] |
Subsequent Event | Subsequent Event Sale of Essentia On January 2, 2013, OneBeacon completed the sale of Essentia Insurance Company (“Essentia”), an indirect wholly owned subsidiary that wrote policies for the Hagerty collector car and boat business, to Markel Corporation. OneBeacon will recognize a pre-tax gain on sale of approximately $23 million ($15 million after tax) in the first quarter of 2013. The Hagerty business associated with this agreement generated net written premiums of approximately $179.7 million, $166.6 million and $153 million (8.0% of WhiteMountains’ consolidated written premiums for all periods), for the years ended December 31, 2012, 2011 and 2010.

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- Definition The entire disclosure for significant events or transactions that occurred after the balance sheet date through the date the financial statements were issued or the date the financial statements were available to be issued. Examples include: the sale of a capital stock issue, purchase of a business, settlement of litigation, catastrophic loss, significant foreign exchange rate changes, loans to insiders or affiliates, and transactions not in the ordinary course of business. + References No definition available. + Details
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