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Income Taxes (Net Operating and Capital Loss Carryforwards) (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2015 | Dec. 31, 2014 | Dec. 31, 2013
Net deferred tax assets |  |  |
Total net deferred income tax assets | $ 215.0 | $ 207.6 |
Change in valuation allowance | 18.7 | 36.0 | $ 49.9
Alternative minimum tax credit carryforwards, not subject to expiration | 1.9 |  |
Tax credit carryforwards | 16.9 | 13.4 |
UNITED STATES |  |  |
Summary of net operating loss and capital loss carryforwards, the expiration dates and the deferred tax assets thereon |  |  |
Operating Loss Carryforwards | 22.6 |  |
Net deferred tax assets |  |  |
Foreign tax credit carryforwards, subject to expiration | 0.4 |  |
Tax credit carryforwards | 14.6 |  |
Operating and Capital Loss Carryforward |  |  |
Summary of net operating loss and capital loss carryforwards, the expiration dates and the deferred tax assets thereon |  |  |
Operating Loss Carryforwards | 662.3 |  |
Net deferred tax assets |  |  |
Gross deferred tax asset | 220.5 |  |
Valuation allowance | (155.1) |  |
Total net deferred income tax assets | 65.4 |  |
Operating and Capital Loss Carryforward | UNITED STATES |  |  |
Summary of net operating loss and capital loss carryforwards, the expiration dates and the deferred tax assets thereon |  |  |
Operating Loss Carryforwards | 543.4 |  |
Net deferred tax assets |  |  |
Gross deferred tax asset | 186.6 |  |
Valuation allowance | (121.2) |  |
Total net deferred income tax assets | 65.4 |  |
Operating and Capital Loss Carryforward | Luxembourg |  |  |
Summary of net operating loss and capital loss carryforwards, the expiration dates and the deferred tax assets thereon |  |  |
Operating Loss Carryforwards | 96.8 |  |
Net deferred tax assets |  |  |
Gross deferred tax asset | 28.3 |  |
Valuation allowance | (28.3) |  |
Total net deferred income tax assets | 0.0 |  |
Operating and Capital Loss Carryforward | Foreign Tax Authority [Member] |  |  |
Summary of net operating loss and capital loss carryforwards, the expiration dates and the deferred tax assets thereon |  |  |
Operating Loss Carryforwards | 21.8 |  |
Net deferred tax assets |  |  |
Gross deferred tax asset | 5.5 |  |
Valuation allowance | (5.5) |  |
Total net deferred income tax assets | 0.0 |  |
Operating and Capital Loss Carryforward | NETHERLANDS |  |  |
Summary of net operating loss and capital loss carryforwards, the expiration dates and the deferred tax assets thereon |  |  |
Operating Loss Carryforwards | 0.3 |  |
Net deferred tax assets |  |  |
Gross deferred tax asset | 0.1 |  |
Valuation allowance | (0.1) |  |
Total net deferred income tax assets | 0.0 |  |
No expiration date [Member] | Operating and Capital Loss Carryforward |  |  |
Summary of net operating loss and capital loss carryforwards, the expiration dates and the deferred tax assets thereon |  |  |
Operating Loss Carryforwards | 118.6 |  |
No expiration date [Member] | Operating and Capital Loss Carryforward | UNITED STATES |  |  |
Summary of net operating loss and capital loss carryforwards, the expiration dates and the deferred tax assets thereon |  |  |
Operating Loss Carryforwards | 0.0 |  |
No expiration date [Member] | Operating and Capital Loss Carryforward | Luxembourg |  |  |
Summary of net operating loss and capital loss carryforwards, the expiration dates and the deferred tax assets thereon |  |  |
Operating Loss Carryforwards | 96.8 |  |
No expiration date [Member] | Operating and Capital Loss Carryforward | Foreign Tax Authority [Member] |  |  |
Summary of net operating loss and capital loss carryforwards, the expiration dates and the deferred tax assets thereon |  |  |
Operating Loss Carryforwards | 21.8 |  |
No expiration date [Member] | Operating and Capital Loss Carryforward | NETHERLANDS |  |  |
Summary of net operating loss and capital loss carryforwards, the expiration dates and the deferred tax assets thereon |  |  |
Operating Loss Carryforwards | 0.0 |  |
2026-2035 | Operating and Capital Loss Carryforward |  |  |
Summary of net operating loss and capital loss carryforwards, the expiration dates and the deferred tax assets thereon |  |  |
Operating Loss Carryforwards | 540.6 |  |
2026-2035 | Operating and Capital Loss Carryforward | UNITED STATES |  |  |
Summary of net operating loss and capital loss carryforwards, the expiration dates and the deferred tax assets thereon |  |  |
Operating Loss Carryforwards | 540.6 |  |
2026-2035 | Operating and Capital Loss Carryforward | Luxembourg |  |  |
Summary of net operating loss and capital loss carryforwards, the expiration dates and the deferred tax assets thereon |  |  |
Operating Loss Carryforwards | 0.0 |  |
2026-2035 | Operating and Capital Loss Carryforward | Foreign Tax Authority [Member] |  |  |
Summary of net operating loss and capital loss carryforwards, the expiration dates and the deferred tax assets thereon |  |  |
Operating Loss Carryforwards | 0.0 |  |
2026-2035 | Operating and Capital Loss Carryforward | NETHERLANDS |  |  |
Summary of net operating loss and capital loss carryforwards, the expiration dates and the deferred tax assets thereon |  |  |
Operating Loss Carryforwards | 0.0 |  |
2021-2025 | Operating and Capital Loss Carryforward |  |  |
Summary of net operating loss and capital loss carryforwards, the expiration dates and the deferred tax assets thereon |  |  |
Operating Loss Carryforwards | 2.3 |  |
2021-2025 | Operating and Capital Loss Carryforward | UNITED STATES |  |  |
Summary of net operating loss and capital loss carryforwards, the expiration dates and the deferred tax assets thereon |  |  |
Operating Loss Carryforwards | 2.0 |  |
2021-2025 | Operating and Capital Loss Carryforward | Luxembourg |  |  |
Summary of net operating loss and capital loss carryforwards, the expiration dates and the deferred tax assets thereon |  |  |
Operating Loss Carryforwards | 0.0 |  |
2021-2025 | Operating and Capital Loss Carryforward | Foreign Tax Authority [Member] |  |  |
Summary of net operating loss and capital loss carryforwards, the expiration dates and the deferred tax assets thereon |  |  |
Operating Loss Carryforwards | 0.0 |  |
2021-2025 | Operating and Capital Loss Carryforward | NETHERLANDS |  |  |
Summary of net operating loss and capital loss carryforwards, the expiration dates and the deferred tax assets thereon |  |  |
Operating Loss Carryforwards | 0.3 |  |
2016-2020 | Operating and Capital Loss Carryforward |  |  |
Summary of net operating loss and capital loss carryforwards, the expiration dates and the deferred tax assets thereon |  |  |
Operating Loss Carryforwards | 0.8 |  |
2016-2020 | Operating and Capital Loss Carryforward | UNITED STATES |  |  |
Summary of net operating loss and capital loss carryforwards, the expiration dates and the deferred tax assets thereon |  |  |
Operating Loss Carryforwards | 0.8 |  |
2016-2020 | Operating and Capital Loss Carryforward | Luxembourg |  |  |
Summary of net operating loss and capital loss carryforwards, the expiration dates and the deferred tax assets thereon |  |  |
Operating Loss Carryforwards | 0.0 |  |
2016-2020 | Operating and Capital Loss Carryforward | Foreign Tax Authority [Member] |  |  |
Summary of net operating loss and capital loss carryforwards, the expiration dates and the deferred tax assets thereon |  |  |
Operating Loss Carryforwards | 0.0 |  |
2016-2020 | Operating and Capital Loss Carryforward | NETHERLANDS |  |  |
Summary of net operating loss and capital loss carryforwards, the expiration dates and the deferred tax assets thereon |  |  |
Operating Loss Carryforwards | 0.0 |  |
Star & Shield Insurance Exchange [Member] |  |  |
Net deferred tax assets |  |  |
Change in valuation allowance | $ (1.2) | $ (3.2) |

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