Significant Transactions	12 Months Ended
Dec. 31, 2014
Significant Transactions [Abstract]
Significant Transactions	Significant Transactions Acquisitions The following acquisitions are included in White Mountains’s consolidated financial statements from the date of acquisition. The total assets acquired and liabilities assumed have been measured at their acquisition date fair values. Olympus In December 2014, Sirius Group acquired 100% of Olympus Reinsurance Company, Ltd. (“Olympus Re”) for $11.5 million. Olympus Re is a Bermuda-domiciled insurance and reinsurance company that assumed property and marine business from Sirius Group from 2001 to 2007 and has been in runoff since then. At acquisition, Sirius Group recognized total assets acquired of $24.6 million and total liabilities assumed of $13.1 million at their estimated fair values. Tranzact On October 10, 2014, White Mountains acquired majority ownership of Tranzact, a leading provider of end-to-end, performance-driven customer acquisition solutions to the insurance sector. White Mountains acquired 63.2% of Tranzact for a purchase price of $177.7 million, representing an enterprise value of $281.2 million. Immediately following the closing, Tranzact completed a recapitalization that allowed for the return of $44.2 million in capital to White Mountains. As of the acquisition date, White Mountains recognized total assets acquired related to Tranzact of $332.8 million, including $41.4 million of tangible assets, $145.1 million of goodwill, and $146.3 million of other intangible assets; and total liabilities assumed of $108.7 million at their estimated fair values. The liabilities assumed include a contingent consideration liability of $7.4 million associated with a prior acquisition by Tranzact. The contingent consideration is payable if earnings before interest expense, taxes, depreciation and amortization (“EBITDA”) of the acquiree exceed amounts defined in the purchase agreement. QuoteLab On March 14, 2014, White Mountains acquired 60.0% of the outstanding Class A common units of QuoteLab. QuoteLab is a California-based advertising technology company offering a transparent online exchange and sophisticated analytical tools that facilitate transactions between buyers (advertisers) and sellers (publishers) of insurance media (clicks and calls), including its own media inventory generated by owned and operated websites. Its exchange operates in four verticles: auto, home, health and life. White Mountains paid an initial purchase price of $28.1 million. The purchase price is subject to adjustment equal to 62.5% of the 2015 gross profit in excess of the 2013 gross profit. As of December 31, 2014, White Mountains has recognized a $7.9 million liability for the contingent purchase price adjustment. After adjustment for the estimated contingent purchase price adjustment, White Mountains recognized total assets acquired related to QuoteLab of $70.1 million, including $18.3 million of goodwill and $38.5 million of other intangible assets; and total liabilities assumed of $10.0 million, reflecting acquisition date fair values. Wobi On February 19, 2014, White Mountains acquired 54.0% of the outstanding common shares of Wobi for NIS 14.4 million (approximately $4.1 million based upon the foreign exchange spot rate at the date of acquisition). During 2014, in addition to the common shares, White Mountains also purchased NIS 31.5 million (approximately $9.0 million based upon the foreign exchange spot rate at the dates of acquisition) of newly-issued convertible preferred shares of Wobi. As of December 31, 2014 White Mountains’s ownership share was 63.3% on a fully converted basis. Wobi is the only insurance price comparison/aggregation business in Israel, with a carrier panel that represents 85% of the premiums written in the Israeli insurance market. Wobi sells four lines of business, primarily personal auto, and operates as an agency, charging upfront commissions on all policy sales. As of the acquisition date, White Mountains recognized total assets acquired related to Wobi of $13.4 million, including $5.5 million of goodwill and $2.9 million of other intangible assets; and total liabilities assumed of $0.7 million at their estimated fair values. WM Solutions In the first quarter of 2013, WM Solutions acquired Ashmere Insurance Company (“Ashmere”, formerly known as American Fuji Fire and Marine Insurance Company), an American International Group, Inc. (“AIG”) runoff subsidiary. The transaction resulted in a gain of $6.9 million recorded in other revenue. On October 15, 2013, WM Solutions acquired Empire Insurance Company (“Empire”), a runoff insurance subsidiary of Leucadia National Corporation. The transaction resulted in a gain of $7.3 million recorded in other revenue. On December 3, 2012, WM Solutions acquired four runoff entities including Physicians Insurance Company of Ohio (“PICO”) and Citation Insurance Company (“Citation”) from PICO Holdings and two AIG runoff subsidiaries, Woodridge Insurance Company (“Woodridge”, formerly known as American General Indemnity Company) and Oakwood Insurance Company (“Oakwood”, formerly known as American General Property Insurance Company). The transactions resulted in a gain of $14.5 million recorded in other revenue. Star & Shield On January 31, 2014, White Mountains acquired certain assets and liabilities of Star & Shield Holdings LLC, including SSRM, the attorney-in-fact for SSIE, for a purchase price of $1.8 million. During 2014, White Mountains also purchased $17.0 million of surplus notes issued by SSIE. Principal and interest on the surplus notes are payable to White Mountains only with approval from the Florida Office of Insurance Regulation. SSIE is a Florida-domiciled reciprocal insurance exchange providing private passenger auto insurance to the public safety community and their families. SSIE is a VIE. As a result of SSRM’s role as the attorney-in-fact to SSIE and the investment in SSIE’s surplus notes, White Mountains is required to consolidate SSIE. As of December 31, 2014, consolidated amounts included total assets of $13.5 million and total liabilities of $25.9 million of SSIE. For the twelve months ended December 31, 2014, SSIE had pre-tax losses of $12.4 million that were recorded in net loss attributable to non-controlling interests. Formation of HG Global and BAM In 2012, White Mountains capitalized HG Global with $594.5 million to fund BAM, a newly formed mutual municipal bond insurer. HG Global, together with its subsidiaries, provided the initial capitalization of BAM through the purchase of $503.0 million of BAM Surplus Notes. (See Note 10 and Note 18) Dispositions Sale of OneBeacon Runoff Business On December 23, 2014, OneBeacon completed the sale of its Runoff Business to Trebuchet US Holdings, Inc., a wholly-owned subsidiary of Armour Group Holdings Limited (“Armour”). Financing was provided in the form of surplus notes of $101.0 million that had a fair value of $64.9 million. These surplus notes are presented within other investments (see Note 5). The difference of $36.1 million between the par value and the fair value of the surplus notes at the date of sale is included in the loss from sale of discontinued operations (see Note 22). WM Solutions In October 2014, White Mountains Solutions entered into an agreement to sell Ashmere to Agency Bonding Captives, Inc. as a “shell company” for $6.0 million in excess of statutory surplus, which is expected to result in a GAAP pre-tax gain of under $1.0 million. The liabilities of Ashmere were transferred to a Sirius Group affiliate during the fourth quarter of 2014 and the transaction is expected to close during the first quarter of 2015 subject to receipt of all necessary regulatory approvals. In the first quarter of 2014, WM Solutions completed the shell sale of Citation Insurance Company, which resulted in a gain of $0.7 million recorded in other revenue. Sale of Essentia Insurance Company Effective January 1, 2013, OneBeacon completed the sale of Essentia Insurance Company (“Essentia”), an indirect wholly-owned subsidiary which wrote the collector cars and boats business, to Markel Corporation. Concurrently therewith, OneBeacon and Hagerty Insurance Agency (“Hagerty”) terminated their underwriting arrangement with respect to the collector cars and boats business. OneBeacon recognized a pre-tax gain on sale of $23.0 million ($15.0 million after tax) in the first quarter of 2013. The business associated with this agreement generated net written premiums of $179.7 million or 8.0% of White Mountains’s net written premiums for December 31, 2012. Sale of AutoOne On August 30, 2011, OneBeacon entered into a definitive agreement (the “Purchase Agreement”) to sell the AutoOne business to Interboro Holdings, Inc. (“Interboro”). 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 22).

Significant Transactions

Acquisitions

The following acquisitions are included in White Mountains’s consolidated financial statements from the date of acquisition. The total assets acquired and liabilities assumed have been measured at their acquisition date fair values.

Olympus

In December 2014, Sirius Group acquired 100% of Olympus Reinsurance Company, Ltd. (“Olympus Re”) for $11.5 million. Olympus Re is a Bermuda-domiciled insurance and reinsurance company that assumed property and marine business from Sirius Group from 2001 to 2007 and has been in runoff since then. At acquisition, Sirius Group recognized total assets acquired of $24.6 million and total liabilities assumed of $13.1 million at their estimated fair values.

Tranzact

On October 10, 2014, White Mountains acquired majority ownership of Tranzact, a leading provider of end-to-end, performance-driven customer acquisition solutions to the insurance sector. White Mountains acquired 63.2% of Tranzact for a purchase price of $177.7 million, representing an enterprise value of $281.2 million. Immediately following the closing, Tranzact completed a recapitalization that allowed for the return of $44.2 million in capital to White Mountains. As of the acquisition date, White Mountains recognized total assets acquired related to Tranzact of $332.8 million, including $41.4 million of tangible assets, $145.1 million of goodwill, and $146.3 million of other intangible assets; and total liabilities assumed of $108.7 million at their estimated fair values. The liabilities assumed include a contingent consideration liability of $7.4 million associated with a prior acquisition by Tranzact. The contingent consideration is payable if earnings before interest expense, taxes, depreciation and amortization (“EBITDA”) of the acquiree exceed amounts defined in the purchase agreement.

QuoteLab

On March 14, 2014, White Mountains acquired 60.0% of the outstanding Class A common units of QuoteLab. QuoteLab is a California-based advertising technology company offering a transparent online exchange and sophisticated analytical tools that facilitate transactions between buyers (advertisers) and sellers (publishers) of insurance media (clicks and calls), including its own media inventory generated by owned and operated websites. Its exchange operates in four verticles: auto, home, health and life. White Mountains paid an initial purchase price of $28.1 million. The purchase price is subject to adjustment equal to 62.5% of the 2015 gross profit in excess of the 2013 gross profit. As of December 31, 2014, White Mountains has recognized a $7.9 million liability for the contingent purchase price adjustment. After adjustment for the estimated contingent purchase price adjustment, White Mountains recognized total assets acquired related to QuoteLab of $70.1 million, including $18.3 million of goodwill and $38.5 million of other intangible assets; and total liabilities assumed of $10.0 million, reflecting acquisition date fair values.

Wobi

On February 19, 2014, White Mountains acquired 54.0% of the outstanding common shares of Wobi for NIS 14.4 million (approximately $4.1 million based upon the foreign exchange spot rate at the date of acquisition). During 2014, in addition to the common shares, White Mountains also purchased NIS 31.5 million (approximately $9.0 million based upon the foreign exchange spot rate at the dates of acquisition) of newly-issued convertible preferred shares of Wobi. As of December 31, 2014 White Mountains’s ownership share was 63.3% on a fully converted basis. Wobi is the only insurance price comparison/aggregation business in Israel, with a carrier panel that represents 85% of the premiums written in the Israeli insurance market. Wobi sells four lines of business, primarily personal auto, and operates as an agency, charging upfront commissions on all policy sales. As of the acquisition date, White Mountains recognized total assets acquired related to Wobi of $13.4 million, including $5.5 million of goodwill and $2.9 million of other intangible assets; and total liabilities assumed of $0.7 million at their estimated fair values.

WM Solutions

In the first quarter of 2013, WM Solutions acquired Ashmere Insurance Company (“Ashmere”, formerly known as American Fuji Fire and Marine Insurance Company), an American International Group, Inc. (“AIG”) runoff subsidiary. The transaction resulted in a gain of $6.9 million recorded in other revenue.

On October 15, 2013, WM Solutions acquired Empire Insurance Company (“Empire”), a runoff insurance subsidiary of Leucadia National Corporation. The transaction resulted in a gain of $7.3 million recorded in other revenue.

On December 3, 2012, WM Solutions acquired four runoff entities including Physicians Insurance Company of Ohio (“PICO”) and Citation Insurance Company (“Citation”) from PICO Holdings and two AIG runoff subsidiaries, Woodridge Insurance Company (“Woodridge”, formerly known as American General Indemnity Company) and Oakwood Insurance Company (“Oakwood”, formerly known as American General Property Insurance Company). The transactions resulted in a gain of $14.5 million recorded in other revenue.

Star & Shield

On January 31, 2014, White Mountains acquired certain assets and liabilities of Star & Shield Holdings LLC, including SSRM, the attorney-in-fact for SSIE, for a purchase price of $1.8 million.

During 2014, White Mountains also purchased $17.0 million of surplus notes issued by SSIE. Principal and interest on the surplus notes are payable to White Mountains only with approval from the Florida Office of Insurance Regulation.

SSIE is a Florida-domiciled reciprocal insurance exchange providing private passenger auto insurance to the public safety community and their families. SSIE is a VIE. As a result of SSRM’s role as the attorney-in-fact to SSIE and the investment in SSIE’s surplus notes, White Mountains is required to consolidate SSIE. As of December 31, 2014, consolidated amounts included total assets of $13.5 million and total liabilities of $25.9 million of SSIE. For the twelve months ended December 31, 2014, SSIE had pre-tax losses of $12.4 million that were recorded in net loss attributable to non-controlling interests.

Formation of HG Global and BAM

In 2012, White Mountains capitalized HG Global with $594.5 million to fund BAM, a newly formed mutual municipal bond insurer. HG Global, together with its subsidiaries, provided the initial capitalization of BAM through the purchase of $503.0 million of BAM Surplus Notes. (See Note 10 and Note 18)

Dispositions

Sale of OneBeacon Runoff Business

On December 23, 2014, OneBeacon completed the sale of its Runoff Business to Trebuchet US Holdings, Inc., a wholly-owned subsidiary of Armour Group Holdings Limited (“Armour”). Financing was provided in the form of surplus notes of $101.0 million that had a fair value of $64.9 million. These surplus notes are presented within other investments (see Note 5). The difference of $36.1 million between the par value and the fair value of the surplus notes at the date of sale is included in the loss from sale of discontinued operations (see Note 22).

WM Solutions

In October 2014, White Mountains Solutions entered into an agreement to sell Ashmere to Agency Bonding Captives, Inc. as a “shell company” for $6.0 million in excess of statutory surplus, which is expected to result in a GAAP pre-tax gain of under $1.0 million. The liabilities of Ashmere were transferred to a Sirius Group affiliate during the fourth quarter of 2014 and the transaction is expected to close during the first quarter of 2015 subject to receipt of all necessary regulatory approvals.

In the first quarter of 2014, WM Solutions completed the shell sale of Citation Insurance Company, which resulted in a gain of $0.7 million recorded in other revenue.

Sale of Essentia Insurance Company

Effective January 1, 2013, OneBeacon completed the sale of Essentia Insurance Company (“Essentia”), an indirect wholly-owned subsidiary which wrote the collector cars and boats business, to Markel Corporation. Concurrently therewith, OneBeacon and Hagerty Insurance Agency (“Hagerty”) terminated their underwriting arrangement with respect to the collector cars and boats business. OneBeacon recognized a pre-tax gain on sale of $23.0 million ($15.0 million after tax) in the first quarter of 2013. The business associated with this agreement generated net written premiums of $179.7 million or 8.0% of White Mountains’s net written premiums for December 31, 2012.

Sale of AutoOne

On August 30, 2011, OneBeacon entered into a definitive agreement (the “Purchase Agreement”) to sell the AutoOne business to Interboro Holdings, Inc. (“Interboro”). 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 22).