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Investment Securities OneBeacon Surplus Notes (Details) - USD ($) $ in Millions | 3 Months Ended | 12 Months Ended |
--- | --- | --- | ---
Mar. 31, 2016 | Mar. 31, 2015 | Dec. 31, 2015 | Dec. 23, 2014
Equity in earnings of unconsolidated affiliates, net of tax | $ 0.0 | $ 7.3 |  |
Interest Paid | 1.6 | $ 0.0 |  |
OneBeacon [Member] |  |  |  |
Assets, Fair Value Adjustment | (49.2) |  | $ (49.5) |
OneBeacon [Member] | Par Value [Member] |  |  |  |
Surplus Notes | 101.0 |  | 101.0 | $ 101.0
OneBeacon [Member] | Fair Value [Member] |  |  |  |
Surplus Notes | 51.8 |  | 51.5 |
OneBeacon [Member] | Current market rates on repayments [Member] |  |  |  |
Assets, Fair Value Adjustment | (14.7) |  | (15.1) |
OneBeacon [Member] | Regulatory Approval [Member] |  |  |  |
Assets, Fair Value Adjustment | (24.4) |  | (24.2) |
OneBeacon [Member] | Liquidity Adjustment [Member] |  |  |  |
Assets, Fair Value Adjustment | (10.1) |  | $ (10.2) |
Seller Priority Surplus Note [Member] | OneBeacon [Member] |  |  |  |
Assets, Fair Value Adjustment | (19.7) |  |  |
Seller Priority Surplus Note [Member] | OneBeacon [Member] | Par Value [Member] |  |  |  |
Surplus Notes | 57.9 |  |  |
Seller Priority Surplus Note [Member] | OneBeacon [Member] | Fair Value [Member] |  |  |  |
Surplus Notes | 38.2 |  |  |
Seller Priority Surplus Note [Member] | OneBeacon [Member] | Current market rates on repayments [Member] |  |  |  |
Assets, Fair Value Adjustment | (0.5) |  |  |
Seller Priority Surplus Note [Member] | OneBeacon [Member] | Regulatory Approval [Member] |  |  |  |
Assets, Fair Value Adjustment | (11.4) |  |  |
Seller Priority Surplus Note [Member] | OneBeacon [Member] | Liquidity Adjustment [Member] |  |  |  |
Assets, Fair Value Adjustment | (7.8) |  |  |
Surplus Note |  |  |  |
Interest Paid | 2.4 |  |  |
Pari Passu Surplus Note [Member] | OneBeacon [Member] |  |  |  |
Assets, Fair Value Adjustment | (29.5) |  |  |
Pari Passu Surplus Note [Member] | OneBeacon [Member] | Par Value [Member] |  |  |  |
Surplus Notes | 43.1 |  |  |
Pari Passu Surplus Note [Member] | OneBeacon [Member] | Fair Value [Member] |  |  |  |
Surplus Notes | 13.6 |  |  |
Pari Passu Surplus Note [Member] | OneBeacon [Member] | Current market rates on repayments [Member] |  |  |  |
Assets, Fair Value Adjustment | (14.2) |  |  |
Pari Passu Surplus Note [Member] | OneBeacon [Member] | Regulatory Approval [Member] |  |  |  |
Assets, Fair Value Adjustment | (13.0) |  |  |
Pari Passu Surplus Note [Member] | OneBeacon [Member] | Liquidity Adjustment [Member] |  |  |  |
Assets, Fair Value Adjustment | $ (2.3) |  |  |
Surplus Note |  |  |  |
RBC Score |  |  | 250.00% |

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