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Income Taxes (Effective Rate Reconciliation) (Details) - USD ($) $ in Millions |  |  | 3 Months Ended | 12 Months Ended
--- | --- | --- | --- | ---
Dec. 22, 2017 | Dec. 21, 2017 | Dec. 31, 2017 | Sep. 30, 2017 | Jun. 30, 2017 | Mar. 31, 2017 | Dec. 31, 2016 | Sep. 30, 2016 | Jun. 30, 2016 | Mar. 31, 2016 | Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015
Income Tax Contingency [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
U.S. statutory rate (as a percent) | 21.00% | 35.00% |  |  |  |  |  |  |  |  | 35.00% |  |
Tax expense (benefit) at the U.S. statutory rate |  |  |  |  |  |  |  |  |  |  | $ (2.7) | $ 51.6 | $ (45.2)
Differences in taxes resulting from: |  |  |  |  |  |  |  |  |  |  |  |  |
Tax rate changes |  |  |  |  |  |  |  |  |  |  | (44.3) | (3.9) | (0.5)
Change in valuation allowance |  |  |  |  |  |  |  |  |  |  | 42.6 | 6.9 | (21.8)
Non-U.S. earnings, net of foreign taxes |  |  |  |  |  |  |  |  |  |  | 21.5 | (19.2) | 58.5
Officer compensation |  |  |  |  |  |  |  |  |  |  | (4.1) | 0.0 | 0.0
Member surplus contributions |  |  |  |  |  |  |  |  |  |  | (3.0) | (2.3) | (1.5)
Withholding tax |  |  |  |  |  |  |  |  |  |  | (2.0) | (0.2) | (0.5)
Tax exempt interest and dividends |  |  |  |  |  |  |  |  |  |  | 0.5 | 0.1 | 0.0
Tax reserve adjustments |  |  |  |  |  |  |  |  |  |  | (0.3) | 0.0 | 0.0
Other, net |  |  |  |  |  |  |  |  |  |  | (0.4) | (0.1) | (1.7)
Income Tax Expense (Benefit) |  |  | $ 2.5 | $ 4.0 | $ 1.0 | $ 0.3 | $ 10.2 | $ 17.1 | $ 4.0 | $ 1.6 | 7.8 | 32.9 | (12.7)
Pre-tax (loss) income from continuing operations |  |  | $ 5.2 | $ 8.4 | $ (2.2) | $ (3.6) | $ (74.5) | $ (13.8) | $ (25.7) | $ (33.3) | 7.8 | (147.3) | 129.2
Tax Payments and Receipts |  |  |  |  |  |  |  |  |  |  |  |  |
Net income tax payments to (receipts from) national governments, total |  |  |  |  |  |  |  |  |  |  | 2.0 | 0.3 | 0.7
Non-US |  |  |  |  |  |  |  |  |  |  |  |  |
Differences in taxes resulting from: |  |  |  |  |  |  |  |  |  |  |  |  |
Pre-tax (loss) income from continuing operations |  |  |  |  |  |  |  |  |  |  | $ 71.3 | $ (66.3) | $ 149.5

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