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Investments in Unconsolidated Affiliates (Tables) | 12 Months Ended
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Dec. 31, 2016
Investments in and Advances to Affiliates [Line Items] |
Schedule of investments in unconsolidated affiliates | White Mountains’s investments in unconsolidated affiliates represent investments in other companies in which White Mountains has a significant voting and economic interest but does not control the entity.
Schedule of changes in unconsolidated affiliates | The following table summarizes amounts recorded by White Mountains under the equity method relating to its investment in Symetra through November 5, 2015:
Millions |  |
Equity method carrying value of investment in Symetra as of December 31, 2014 (1) |  | $ | 411.4 |
Equity in earnings (2)(3)(4) |  | 25.1 |
Equity in net unrealized investment losses from Symetra’s fixed maturity portfolio (5)(6) |  | (39.2 | )
Distribution from Prospector Offshore Fund (7) |  | 12.4 |
Dividends received |  | (16.9 | )
Equity method carrying value of investment in Symetra as of November 5, 2015(1)(8) |  | $ | 392.8 |
(1) | Includes White Mountains’s equity in net unrealized investment (losses) gains from Symetra’s fixed maturity portfolio of $(1.6) and $37.6, as of November 5, 2015 and December 31, 2014, which excludes tax benefit (expense) of $0.2 and $(2.7).
(2) | Equity in earnings for the period ended November 5, 2015 excludes tax expense of $1.6.
(3) | Equity in earnings for the period ended November 5, 2015 includes an increase of $2.3 relating to the pre-tax amortization of the Symetra common share basis difference.
(4) | Equity in earnings for the period ended November 5, 2015 includes losses of $(0.1) from the dilutive effect of Symetra’s yearly dividend and the issuance of restricted shares by Symetra
(5) | Net unrealized investment losses for the period ended November 5, 2015 includes an increase of $9.4 relating to the pre-tax amortization of the Symetra common share basis difference.
(6) | Net unrealized investment losses from Symetra’s fixed maturity portfolio excludes a tax benefit of $2.9 for the period ended November 5, 2015.
(7) | During 2015, pursuant to the redemption of White Mountains's investments in the Prospector Funds, 513,500 common shares of Symetra were distributed to White Mountains.
(8) | The aggregate value of White Mountains’s investment in common shares of Symetra was $651.2 based upon the quoted market price of $31.67 per share as of November 5, 2015.
Symetra |
Investments in and Advances to Affiliates [Line Items] |
Summarized statement of financial position of Symetra | The following table summarizes financial information for Symetra as of September 30, 2015:
|  | September 30,
Millions |  | 2015
Symetra balance sheet data: |  |  |
Total investments |  | $ | 32,409.2 |
Separate account assets |  | 885.9 |
Total assets |  | 34,962.8 |
Policyholder liabilities |  | 29,492.0 |
Long-term debt |  | 697.5 |
Separate account liabilities |  | 885.9 |
Total liabilities |  | 31,836.7 |
Common shareholders’ equity |  | 3,126.1 |
The following table summarizes financial information for Symetra for the nine months ended September 30, 2015 and year ended December 31, 2014:
|  | Nine months ended September 30, |  | Year ended December 31,
Millions |  | 2015 |  | 2014
Symetra income statement data: |  |  |  |
Net premiums earned |  | $ | 539.3 |  |  | $ | 629.1 |
Net investment income |  | 994.3 |  |  | 1,320.5 |
Total revenues |  | 1,605.9 |  |  | 2,182.4 |
Policy benefits |  | 1,143.7 |  |  | 1,399.7 |
Total expenses |  | 1,543.6 |  |  | 1,882.5 |
Net income |  | 89.6 |  |  | 254.4 |
Comprehensive net (loss) income |  | (234.1 | ) |  | 397.0 |

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- Definition Tabular disclosure of investments in and advances to affiliates. Does not include the tabular disclosure of the disaggregation of investments in and advances to affiliates across legal entities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 946 -SubTopic 320 -Section S99 -Paragraph 6 -Subparagraph (SX 210.12-14) -URI http://asc.fasb.org/extlink&oid=50485924&loc=d3e611322-123010 + Details
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