Significant Transactions	9 Months Ended
Sep. 30, 2012
Significant Transactions Disclosure
Significant Transactions	Significant Transactions Formation of HG Global and BAM In July 2012, White Mountains capitalized HG Global with $594.5 million to fund BAM, a newly formed mutual municipal bond insurer. As of September 30, 2012, White Mountains owned 97% of HG Global's preferred equity and 89% of its common equity. HG Global provided the initial capitalization of BAM through the purchase of $503.0 million of BAM surplus notes. Through HG Re, HG Global provides first loss reinsurance protection for policies underwritten by BAM of 15% of par outstanding, on a per policy basis. HG Re's obligations to BAM are collateralized in trusts, and there is an aggregate loss limit that is equal to the total assets in the collateral trusts at any point in time. U.S. GAAP requires White Mountains to consolidate BAM in its financial statements. However, since BAM is a mutual insurance company that is owned by its members and not White Mountains, BAM's results do not affect White Mountains' common shareholders' equity as they are attributable to noncontrolling interests. For the three and nine months ended September 30, 2012, HG Global had pre-tax income of $4.8 million, which included $8.3 million of interest income on the BAM surplus notes. For the three and nine months ended September 30, 2012, BAM had a pre-tax loss of $18.0 million that was recorded in net loss attributable to noncontrolling interests, which included $8.3 million of interest expense on its surplus notes. Sale of OneBeacon runoff business On October 17, 2012, one of OneBeacon's indirect wholly-owned subsidiaries, OneBeacon Insurance Group LLC, entered into a definitive agreement with Trebuchet US Holdings, Inc. (“Trebuchet”), a wholly-owned subsidiary of Armour Group Holdings Limited (together with Trebuchet, “Armour”), to sell its runoff business (the "Runoff Transaction"). Pursuant to the terms of the agreement, at closing OneBeacon will transfer to Trebuchet all of the issued and outstanding shares of common stock of certain legal entities that will contain the assets, liabilities (including gross and ceded loss reserves) and capital supporting the runoff business as well as certain elements of the runoff business infrastructure, including staff and office space. Additionally, as part of the Runoff Transaction, OneBeacon may provide financing in the form of surplus notes. The transaction is subject to regulatory approvals and is expected to close in the second half of 2013. During the third quarter of 2012, OneBeacon recorded $100.5 million in after-tax losses related to the Runoff Transaction. These losses are presented in discontinued operations and are composed of a $91.5 million after-tax loss on sale and a $9.0 million after-tax loss related to an reduction in the workers compensation loss reserve discount rate on reserves being transferred as part of the sale. OneBeacon also recognized $6.5 million of after-tax underwriting losses primarily related to unfavorable loss reserve development from a legacy assumed reinsurance treaty, which is presented in discontinued operations (see Note 14). Sale of AutoOne On February 22, 2012, OneBeacon completed the sale of 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 AutoOne 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). 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 plus 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 (see Note 14). 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 nine months ended September 30, 2012, the Company repurchased 50,000 and 217,801 common shares for $26.4 million and $107.6 million under this program. During the nine months ended September 30, 2011, the Company repurchased 265,768 common shares for $93.2 million. Since the inception of this authorization through September 30, 2012, the Company repurchased 1,629,504 common shares for $645.1 million. At September 30, 2012, the Company may repurchase an additional 970,496 shares under this authorization.

Significant Transactions

Formation of HG Global and BAM

In July 2012, White Mountains capitalized HG Global with $594.5 million to fund BAM, a newly formed mutual municipal bond insurer. As of September 30, 2012, White Mountains owned 97% of HG Global's preferred equity and 89% of its common equity. HG Global provided the initial capitalization of BAM through the purchase of $503.0 million of BAM surplus notes. Through HG Re, HG Global provides first loss reinsurance protection for policies underwritten by BAM of 15% of par outstanding, on a per policy basis. HG Re's obligations to BAM are collateralized in trusts, and there is an aggregate loss limit that is equal to the total assets in the collateral trusts at any point in time. U.S. GAAP requires White Mountains to consolidate BAM in its financial statements. However, since BAM is a mutual insurance company that is owned by its members and not White Mountains, BAM's results do not affect White Mountains' common shareholders' equity as they are attributable to noncontrolling interests. For the three and nine months ended September 30, 2012, HG Global had pre-tax income of $4.8 million, which included $8.3 million of interest income on the BAM surplus notes. For the three and nine months ended September 30, 2012, BAM had a pre-tax loss of $18.0 million that was recorded in net loss attributable to noncontrolling interests, which included $8.3 million of interest expense on its surplus notes.

Sale of OneBeacon runoff business

On October 17, 2012, one of OneBeacon's indirect wholly-owned subsidiaries, OneBeacon Insurance Group LLC, entered into a definitive agreement with Trebuchet US Holdings, Inc. (“Trebuchet”), a wholly-owned subsidiary of Armour Group Holdings Limited (together with Trebuchet, “Armour”), to sell its runoff business (the "Runoff Transaction"). Pursuant to the terms of the agreement, at closing OneBeacon will transfer to Trebuchet all of the issued and outstanding shares of common stock of certain legal entities that will contain the assets, liabilities (including gross and ceded loss reserves) and capital supporting the runoff business as well as certain elements of the runoff business infrastructure, including staff and office space. Additionally, as part of the Runoff Transaction, OneBeacon may provide financing in the form of surplus notes. The transaction is subject to regulatory approvals and is expected to close in the second half of 2013.

During the third quarter of 2012, OneBeacon recorded $100.5 million in after-tax losses related to the Runoff Transaction. These losses are presented in discontinued operations and are composed of a $91.5 million after-tax loss on sale and a $9.0 million after-tax loss related to an reduction in the workers compensation loss reserve discount rate on reserves being transferred as part of the sale. OneBeacon also recognized $6.5 million of after-tax underwriting losses primarily related to unfavorable loss reserve development from a legacy assumed reinsurance treaty, which is presented in discontinued operations (see Note 14).

Sale of AutoOne

On February 22, 2012, OneBeacon completed the sale of 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 AutoOne 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).

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 plus 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 (see Note 14).

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 nine months ended September 30, 2012, the Company repurchased 50,000 and 217,801 common shares for $26.4 million and $107.6 million under this program.

During the nine months ended September 30, 2011, the Company repurchased 265,768 common shares for $93.2 million.

Since the inception of this authorization through September 30, 2012, the Company repurchased 1,629,504 common shares for $645.1 million. At September 30, 2012, the Company may repurchase an additional 970,496 shares under this authorization.