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Subsequent Events | 3 Months Ended
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Mar. 31, 2016
Subsequent Events [Abstract] |
Subsequent Events [Text Block] | Subsequent Events Sirius Group Sale On April 18, 2016, White Mountains completed the sale of Sirius Group to CMI for approximately $2.6 billion. $161.8 million of this amount was used to purchase certain assets to be retained by White Mountains out of Sirius Group, including shares of OneBeacon. The amount paid at closing was based on an estimate of Sirius Group’s closing date tangible common shareholder’s equity. The purchase price will be adjusted upon determination of Sirius Group’s actual closing date tangible common shareholder’s equity. Share Repurchases During April 2016, White Mountains repurchased and retired 356,423 of its common shares for $287 million at an average share price of $806.52, which included 325,000 common shares repurchased from Franklin Mutual Advisers for $807.00 per share, the market price at the time the agreement was reached.

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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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