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Variable Interest Entities (Details) $ in Millions | 3 Months Ended | 12 Months Ended
--- | --- | ---
Dec. 31, 2016 USD ($) trust | Sep. 30, 2016 USD ($) | Jun. 30, 2016 USD ($) | Mar. 31, 2016 USD ($) | Dec. 31, 2015 USD ($) | Sep. 30, 2015 USD ($) | Jun. 30, 2015 USD ($) | Mar. 31, 2015 USD ($) | Dec. 31, 2016 USD ($) trust director | Dec. 31, 2015 USD ($) | Dec. 31, 2014 USD ($) | Dec. 31, 2012 USD ($)
Variable Interest Entity [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Percentage of par value of policy reinsured | 15.00% |  |  |  |  |  |  |  | 15.00% |  |  |
Other revenue |  |  |  |  |  |  |  |  | $ 149.6 | $ 147.3 | $ 88.1 |
Accumulated losses | $ 2,797.2 |  |  |  | $ 3,084.9 |  |  |  | 2,797.2 | 3,084.9 |  |
Noncontrolling interest in VIE | 133.9 |  |  |  | 454.8 |  |  |  | 133.9 | 454.8 |  |
Non-controlling interest in consolidated subsidiaries | $ (17.3) | $ (3.1) | $ 21.4 | $ 6.3 | 6.1 | $ (16.0) | $ (0.9) | $ (7.3) | 7.3 | (18.1) | (22.2) |
Payments to Acquire Other Investments |  |  |  |  |  |  |  |  | $ 39.5 | 78.0 | 114.7 |
HG Global |  |  |  |  |  |  |  |  |  |  |  |
Variable Interest Entity [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Percentage of par value of policy reinsured | 15.00% |  |  |  |  |  |  |  | 15.00% |  |  |
Other revenue |  |  |  |  |  |  |  |  | $ 0.0 | 0.0 | $ 0.0 |
Noncontrolling interest in VIE | $ 16.6 |  |  |  | 17.1 |  |  |  | 16.6 | 17.1 |  |
Star & Shield Insurance Exchange [Member] |  |  |  |  |  |  |  |  |  |  |  |
Variable Interest Entity [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Surplus notes |  |  |  |  | 21.0 |  |  |  |  | 21.0 |  |
Total assets related to consolidated VIE's | 9.2 |  |  |  | 14.2 |  |  |  | 9.2 | 14.2 |  |
Total liabilities related to consolidated VIE's | 4.8 |  |  |  | 30.3 |  |  |  | 4.8 | $ 30.3 |  |
Prospector |  |  |  |  |  |  |  |  |  |  |  |
Variable Interest Entity [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Variable Interest Entity, Qualitative or Quantitative Information, Ownership Percentage |  |  |  |  |  |  |  |  |  | 67.60% |  |
Houston General Insurance [Member] |  |  |  |  |  |  |  |  |  |  |  |
Variable Interest Entity [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Surplus notes | 5.0 |  |  |  |  |  |  |  | 5.0 |  |  |
Total assets related to consolidated VIE's | 5.1 |  |  |  |  |  |  |  | 5.1 |  |  |
Total liabilities related to consolidated VIE's | 5.0 |  |  |  |  |  |  |  | 5.0 |  |  |
Accumulated losses | 0.5 |  |  |  |  |  |  |  | 0.5 |  |  |
Accrued interest on surplus notes | 0.6 |  |  |  |  |  |  |  | 0.6 |  |  |
Common Stock | BAM |  |  |  |  |  |  |  |  |  |  |  |
Variable Interest Entity [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Issuance of notes |  |  |  |  |  |  |  |  |  |  |  | $ 503.0
Star & Shield Insurance Exchange [Member] |  |  |  |  |  |  |  |  |  |  |  |
Variable Interest Entity [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Other revenue |  |  |  |  |  |  |  |  | 21.0 |  |  |
Noncontrolling interest in VIE | 4.4 |  |  |  | (16.0) |  |  |  | $ 4.4 | $ (16.0) |  |
BAM |  |  |  |  |  |  |  |  |  |  |  |
Variable Interest Entity [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Right to elect directors on board number | director |  |  |  |  |  |  |  |  | 2 |  |  |
HG Global |  |  |  |  |  |  |  |  |  |  |  |
Variable Interest Entity [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Surplus notes | 300.0 |  |  |  |  |  |  |  | $ 300.0 |  |  | $ 503.0
Noncontrolling interest in VIE | $ 16.6 |  |  |  | $ 17.1 |  |  |  | $ 16.6 | $ 17.1 |  |
First Loss Reinsurance Treaty [Member] | HG Global |  |  |  |  |  |  |  |  |  |  |  |
Variable Interest Entity [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Percentage of par value of policy reinsured | 15.00% |  |  |  |  |  |  |  | 15.00% |  |  |
First Loss Reinsurance Treaty [Member] | BAM |  |  |  |  |  |  |  |  |  |  |  |
Variable Interest Entity [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Percentage of Premiums | 60.00% |  |  |  |  |  |  |  | 60.00% |  |  |
First Loss Reinsurance Treaty [Member] | HG Global |  |  |  |  |  |  |  |  |  |  |  |
Variable Interest Entity [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Number of Trust | trust | 2 |  |  |  |  |  |  |  | 2 |  |  |
Amendment [Member] | Houston General Insurance [Member] |  |  |  |  |  |  |  |  |  |  |  |
Variable Interest Entity [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Surplus notes | $ 5.0 |  |  |  |  |  |  |  | $ 5.0 |  |  |

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