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Contingencies (Details) - USD ($) $ in Millions | 1 Months Ended | 3 Months Ended | 6 Months Ended |
--- | --- | --- | --- | ---
Jun. 30, 2007 | Jun. 30, 2016 | Sep. 30, 2015 | Jun. 30, 2015 | Jun. 30, 2016 | Jun. 30, 2015 | Oct. 07, 2011
Loss Contingencies [Line Items] |  |  |  |  |  |  |
Net gain on sale of discontinued operations |  | $ 366.6 |  | $ (0.1) | $ 366.6 | $ 7.9 |
Esurance |  |  |  |  |  |  |
Loss Contingencies [Line Items] |  |  |  |  |  |  |
Percentage of fluctuation in loss reserves of transferred subsidiaries retained |  |  |  |  |  |  | 90.00%
Tribune Company Litigation | Pending Litigation | OneBeacon [Member] |  |  |  |  |  |  |
Loss Contingencies [Line Items] |  |  |  |  |  |  |
Proceeds from Sale, Maturity and Collection of Investments | $ 32.0 |  |  |  |  |  |
Discontinued Operations [Member] |  |  |  |  |  |  |
Loss Contingencies [Line Items] |  |  |  |  |  |  |
Net gain on sale of discontinued operations |  | (8.0) |  | (0.4) | (6.9) | 62.9 |
Esurance | Discontinued Operations [Member] |  |  |  |  |  |  |
Loss Contingencies [Line Items] |  |  |  |  |  |  |
Net gain on sale of discontinued operations |  |  | $ 10.3 | (0.3) | 28.3 | 7.6 |
OneBeacon Runoff [Member] | Discontinued Operations [Member] |  |  |  |  |  |  |
Loss Contingencies [Line Items] |  |  |  |  |  |  |
Net gain on sale of discontinued operations |  |  |  | 0.3 |  | 0.3 |
Sirius Group |  |  |  |  |  |  |
Loss Contingencies [Line Items] |  |  |  |  |  |  |
Net gain on sale of discontinued operations |  |  |  |  | 366.6 |  |
Sirius Group | Discontinued Operations [Member] |  |  |  |  |  |  |
Loss Contingencies [Line Items] |  |  |  |  |  |  |
Net gain on sale of discontinued operations |  | $ (3.4) |  | $ 3.8 | $ (4.3) | $ 69.7 |

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- Definition Amount after tax of gain (loss) not previously recognized resulting from the disposal of a discontinued operation. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 205 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=51717284&loc=d3e1361-107760 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 205 -SubTopic 20 -Section 45 -Paragraph 3B -URI http://asc.fasb.org/extlink&oid=51716988&loc=SL51721525-107759 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 205 -SubTopic 20 -Section 50 -Paragraph 5C -Subparagraph (b)(2) -URI http://asc.fasb.org/extlink&oid=51717284&loc=SL51721675-107760 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 205 -SubTopic 20 -Section 45 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=51716988&loc=d3e957-107759 + Details
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