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CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY (USD $) In Millions, unless otherwise specified | Total | Non-controlling Interests | Total Equity includes Noncontrolling Interest [Member] | White Mountains Common shareholders’ equity | White Mountains Common shares and paid-in surplus | White Mountains Retained earnings | White Mountains AOCI, after-tax | White Mountains White Mountains excluding noncontrolling interest [Member] | HG Global Common shares and paid-in surplus | HG Global Non-controlling Interests | HG Global Total Equity includes Noncontrolling Interest [Member] | HG Global White Mountains Common shareholders’ equity | HG Global White Mountains Retained earnings | HG Global White Mountains AOCI, after-tax
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Beginning balance at Dec. 31, 2009 |  | $ 684.1 | $ 4,341.5 |  | $ 1,445.0 | $ 2,215.9 | $ (3.5) | $ 3,657.4 |  |  |  |  |  |
Increase (Decrease) in Shareholders' Equity |  |  |  |  |  |  |  |  |  |  |  |  |  |
Cumulative effect adjustment — ASU 2009-17 |  |  | (23.2) |  |  |  |  |  |  |  |  |  |  |
Cumulative effect adjustment — ASU 2009-17 (Accounting Standards Update 2009-17) |  | (22.8) |  | (0.4) | 0 | (0.4) | 0 |  |  |  |  |  |  |
Tax basis change due to intercompany transfer |  | 0 | (10.4) | (10.4) | 0 | (4.4) | (6.0) |  |  |  |  |  |  |
Net income | 139.5 | 53.0 | 139.5 | 86.5 | 0 | 86.5 | 0 |  |  |  |  |  |  |
Net change in unrealized gains from investments in unconsolidated affiliates | 73.5 | 0 | 73.5 | 73.5 | 0 | 0 | 73.5 |  |  |  |  |  |  |
Net change in foreign currency translation | 49.8 | 0 | 49.8 | 49.8 | 0 | 0 | 49.8 |  |  |  |  |  |  |
Net change in pension liability and other accumulated comprehensive items | 6.3 | 1.7 | 6.3 | 4.6 | 0 | 0 | 4.6 |  |  |  |  |  |  |
Comprehensive income (loss) | 216.1 | 54.7 | 269.1 | 214.4 | 0 | 86.5 | 127.9 |  |  |  |  |  |  |
Dividends declared on common shares |  | 0 | (8.8) | (8.8) | 0 | (8.8) | 0 |  |  |  |  |  |  |
Dividends/distributions to non-controlling interests |  | (94.7) | (94.7) | 0 | 0 | 0 | 0 |  |  |  |  |  |  |
Issuances of common shares |  | 0 | 0.7 | 0.7 | 0.7 | 0 | 0 |  |  |  |  |  |  |
Repurchase and retirement of common shares | (225.5) | 0 | (225.6) | (225.6) | (112.4) | (113.2) | 0 |  |  |  |  |  |  |
Contribution from (Distribution to) Non-Controlling Interests |  | (13.6) | (13.6) | 0 | 0 | 0 | 0 |  |  |  |  |  |  |
Amortization of restricted share and option awards |  | 0.1 | 25.8 | 25.7 | 25.7 | 0 | 0 |  |  |  |  |  |  |
Ending balance at Dec. 31, 2010 |  | 607.8 | 4,260.8 |  | 1,359.0 | 2,175.6 | 118.4 | 3,653.0 |  |  |  |  |  |
Increase (Decrease) in Shareholders' Equity |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net income | 809.4 | 41.5 | 809.4 | 767.9 | 0 | 767.9 | 0 |  |  |  |  |  |  |
Net change in unrealized gains from investments in unconsolidated affiliates | (58.5) | 0 | (58.5) | (58.5) | 0 | 0 | (58.5) |  |  |  |  |  |  |
Net change in foreign currency translation | (15.2) | 0 | (15.2) | (15.2) | 0 | 0 | (15.2) |  |  |  |  |  |  |
Net change in pension liability and other accumulated comprehensive items | (10.8) | (2.8) | (10.8) | (8.0) | 0 | 0 | (8.0) |  |  |  |  |  |  |
Comprehensive income (loss) | 683.4 | 38.7 | 724.9 | 686.2 | 0 | 767.9 | (81.7) |  |  |  |  |  |  |
Dividends declared on common shares |  | 0 | (8.0) | (8.0) | 0 | (8.0) | 0 |  |  |  |  |  |  |
Dividends/distributions to non-controlling interests |  | (61.5) | (61.5) | 0 | 0 | 0 | 0 |  |  |  |  |  |  |
Issuances of common shares |  | 0 | 0.9 | 0.9 | 0.9 | 0 | 0 |  |  |  |  |  |  |
Repurchase and retirement of common shares | (253.0) | 0 | (253.0) | (253.0) | (107.2) | (145.8) | 0 |  |  |  |  |  |  |
Contribution from (Distribution to) Non-Controlling Interests |  | (8.6) | (8.6) | 0 | 0 | 0 | 0 |  |  |  |  |  |  |
Amortization of restricted share and option awards |  | 0.4 | 12.4 | 12.0 | 12.0 | 0 | 0 |  |  |  |  |  |  |
Non-controlling interest attributable to intercompany sale of subsidiary |  | 3.4 | 0 | (3.4) | (3.4) | 0 | 0 |  |  |  |  |  |  |
Ending balance at Dec. 31, 2011 | 4,087.7 | 580.2 | 4,667.9 |  | 1,261.3 | 2,789.7 | 36.7 | 4,087.7 |  |  |  |  |  |
Increase (Decrease) in Shareholders' Equity |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net income | 193.4 | (14.0) | 193.4 | 207.4 | 0 | 207.4 | 0 |  |  |  |  |  |  |
Net change in unrealized gains from investments in unconsolidated affiliates | 57.7 | 0 | 57.7 | 57.7 | 0 | 0 | 57.7 |  |  |  |  |  |  |
Net change in foreign currency translation | 39.6 | 0 | 39.6 | 39.6 | 0 | 0 | 39.6 |  |  |  |  |  |  |
Net change in pension liability and other accumulated comprehensive items | (2.9) | (0.8) | (2.9) | (2.1) | 0 | 0 | (2.1) |  |  |  |  |  |  |
Comprehensive income (loss) | 301.8 | (14.8) | 287.8 | 302.6 | 0 | 207.4 | 95.2 |  |  |  |  |  |  |
Dividends declared on common shares |  | 0 | (6.6) | (6.6) | 0 | (6.6) | 0 |  |  |  |  |  |  |
Dividends/distributions to non-controlling interests |  | (39.1) | (39.1) | 0 | 0 | 0 | 0 |  |  |  |  |  |  |
Issuances of common shares |  | 0 | 5.8 | 5.8 | 5.8 | 0 | 0 |  |  |  |  |  |  |
Repurchase and retirement of common shares | (669.1) | 0 | (669.1) | (669.1) | (221.3) | (447.8) | 0 |  |  |  |  |  |  |
Contribution from (Distribution to) Non-Controlling Interests |  | 1.6 | 1.6 | 0 | 0 | 0 | 0 |  |  |  |  |  |  |
Amortization of restricted share and option awards |  | 0.8 | 14.4 | 13.6 | 13.6 | 0 | 0 |  |  |  |  |  |  |
Deconsolidation of Hamer and Bri-Mar |  | (4.5) | (4.5) | 0 | 0 | 0 | 0 |  |  |  |  |  |  |
Allocation of fair value of net assets acquired to non-controlling interests |  |  |  |  |  |  |  |  | (2.2) | 2.2 | 0 | (2.2) | 0 | 0
Ending balance at Dec. 31, 2012 | $ 3,731.8 | $ 526.4 | $ 4,258.2 |  | $ 1,057.2 | $ 2,542.7 | $ 131.9 | $ 3,731.8 |  |  |  |  |  |

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- Definition Fair value of net assets allocated to noncontrolling interests. + References No definition available. + Details
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- Definition In January 2012, White Mountains sold a subsidiary of OneBeacon to a subsidiary of Sirius. The amount disclosed represents the portion of the gain OneBeacon expects to recognize that would be for the benefit of the noncontrolling interest holders of OneBeacon, which was recognized as an adjustment between paid in surplus and noncontrolling interest in 2011. + References No definition available. + Details
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X
- Definition Tax basis change due to intercompany transfer of investment in Symetra common shares. + References No definition available. + Details
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