Significant Transactions	6 Months Ended
Jun. 30, 2012
Significant Transactions Disclosure
Significant Transactions	Significant Transactions Sale of Esurance On October 7, 2011, White Mountains completed the sale of Esurance Insurance and AFI to The Allstate Corporation (“Allstate”) for $700 million in excess of tangible book value. White Mountains recorded a gain on the sale of $677.5 million in discontinued operations in the fourth quarter of 2011. The transaction is subject to a true-up of the estimated tangible book value of the entities sold through the date of closing and certain other contingencies. Sale of AutoOne On February 22, 2012, OneBeacon sold AutoOne to Interboro Holdings, Inc. (“Interboro”). OneBeacon formed AutoOne in 2001 to provide products and services to automobile assigned risk markets primarily in New York and New Jersey. OneBeacon transferred to the buyer AutoOne Insurance Company (“AOIC”) and AutoOne Select Insurance Company (“AOSIC”), which contained the assets, liabilities (including loss reserves and unearned premiums), and the capital of the business, and transferred substantially all of the AutoOne infrastructure including systems and office space as well as certain staff. As a result of the sale, AutoOne is reported as discontinued operations (see Note 14). Acquisition of Old Lyme On December 31, 2011, Sirius Group acquired the run-off loss reserve portfolio of Old Lyme, a Bermuda-based reinsurer in run-off, for $6.0 million in cash and a purchase note for $2.1 million (see Note 6). Share Repurchases On March 22, 2012, White Mountains completed a fixed-price tender offer and repurchased 816,829 of its common shares at $500 per share. The total cost of the share repurchase was $408.6 million, including fees and expenses. During 2011, White Mountains completed two “modified Dutch auction” self-tender offers and repurchased 332,346 of its common shares at an average price of $418 per share. The total cost of the share repurchases was $138.8 million, including fees and expenses. In addition to the tender offers, which were separately authorized, the board of directors has authorized the Company to repurchase its common shares, from time to time, subject to market conditions. In 2006, White Mountains’ board of directors authorized the Company to repurchase up to 1,000,000 of its common shares and in 2010 White Mountains’ board of directors authorized the Company to repurchase an additional 600,000 of its common shares. On May 25, 2012, White Mountains' board of directors authorized the Company to repurchase an additional 1,000,000 of its common shares. Shares may be repurchased on the open market or through privately negotiated transactions. The repurchase authorization does not obligate the Company to acquire any specific number of shares, nor is there a stated expiration date. During the three and six months ended June 30, 2012, the Company repurchased 10,172 and 167,801 common shares for $5.2 million and $81.2 million under this program. During the three and six months ended June 30, 2011, the Company repurchased 19,295 and 265,768 common shares for $7.2 million and $93.2 million. Since the inception of this program through June 30, 2012, the Company repurchased 1,579,504 common shares for $619 million. At June 30, 2012, 1,020,496 shares may still be repurchased under this program.

Significant Transactions

Sale of Esurance

On October 7, 2011, White Mountains completed the sale of Esurance Insurance and AFI to The Allstate Corporation (“Allstate”) for $700 million in excess of tangible book value. White Mountains recorded a gain on the sale of $677.5 million in discontinued operations in the fourth quarter of 2011. The transaction is subject to a true-up of the estimated tangible book value of the entities sold through the date of closing and certain other contingencies.

Sale of AutoOne

On February 22, 2012, OneBeacon sold AutoOne to Interboro Holdings, Inc. (“Interboro”). OneBeacon formed AutoOne in 2001 to provide products and services to automobile assigned risk markets primarily in New York and New Jersey. OneBeacon transferred to the buyer AutoOne Insurance Company (“AOIC”) and AutoOne Select Insurance Company (“AOSIC”), which contained the assets, liabilities (including loss reserves and unearned premiums), and the capital of the business, and transferred substantially all of the AutoOne infrastructure including systems and office space as well as certain staff. As a result of the sale, AutoOne is reported as discontinued operations (see Note 14).

Acquisition of Old Lyme

On December 31, 2011, Sirius Group acquired the run-off loss reserve portfolio of Old Lyme, a Bermuda-based reinsurer in run-off, for $6.0 million in cash and a purchase note for $2.1 million (see Note 6).

Share Repurchases

On March 22, 2012, White Mountains completed a fixed-price tender offer and repurchased 816,829 of its common shares at $500 per share. The total cost of the share repurchase was $408.6 million, including fees and expenses. During 2011, White Mountains completed two “modified Dutch auction” self-tender offers and repurchased 332,346 of its common shares at an average price of $418 per share. The total cost of the share repurchases was $138.8 million, including fees and expenses.

In addition to the tender offers, which were separately authorized, the board of directors has authorized the Company to repurchase its common shares, from time to time, subject to market conditions. In 2006, White Mountains’ board of directors authorized the Company to repurchase up to 1,000,000 of its common shares and in 2010 White Mountains’ board of directors authorized the Company to repurchase an additional 600,000 of its common shares. On May 25, 2012, White Mountains' board of directors authorized the Company to repurchase an additional 1,000,000 of its common shares. Shares may be repurchased on the open market or through privately negotiated transactions. The repurchase authorization does not obligate the Company to acquire any specific number of shares, nor is there a stated expiration date.

During the three and six months ended June 30, 2012, the Company repurchased 10,172 and 167,801 common shares for $5.2 million and $81.2 million under this program. During the three and six months ended June 30, 2011, the Company repurchased 19,295 and 265,768 common shares for $7.2 million and $93.2 million. Since the inception of this program through June 30, 2012, the Company repurchased 1,579,504 common shares for $619 million. At June 30, 2012, 1,020,496 shares may still be repurchased under this program.