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Income Taxes - Quarterly Disclosure (Details9) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2016 | Sep. 30, 2015 | Sep. 30, 2016 | Sep. 30, 2015
Investments, Owned, Federal Income Tax Note [Line Items] |  |  |  |
Income tax (provision) benefit | $ 4.3 | $ (23.4) | $ 64.4 | $ (23.7)
Effective Income Tax Rate Reconciliation, Percent | 0.80% |  | 9.10% |
Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Amount | $ 173.1 | $ 63.9 |  |
Amount of valuation allowance in the effective tax rate |  | 6.00% |  |
Discrete tax benefits (expense) | $ (4.1) |  | $ (0.5) | $ (57.9)
Effective tax rate excluding valuation allowance | 34.10% |  |  |
Discrete Item [Member] |  |  |  |
Investments, Owned, Federal Income Tax Note [Line Items] |  |  |  |
Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Amount |  | $ 56.6 |  |
Part of Effective Tax Rate [Member] |  |  |  |
Investments, Owned, Federal Income Tax Note [Line Items] |  |  |  |
Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Amount |  | $ 7.3 |  |

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