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Income Taxes (Effective Rate Reconciliation) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Contingency [Line Items]
U.S. statutory rate (as a percent)									35.00%
Tax expense (benefit) at the U.S. statutory rate									$ 14.1	$ (55.1)	$ 10.3
Differences in taxes resulting from:
Tax reserve adjustments									13.7	(1.7)	5.2
Change in valuation allowance									9.1	(19.4)	(35.7)
Non-U.S. earnings, net of foreign taxes									6.9	76.7	37.8
Tax rate changes									(3.5)	0.0	0.0
Tax exempt interest and dividends									2.5	2.6	2.5
Other, net									(0.5)	(1.2)	(2.4)
Other, net									3.1	(1.7)	(2.9)
Income Tax Expense (Benefit)	$ 23.0	$ 6.7	$ 6.0	$ 9.7	$ 1.0	$ 1.6	$ 2.2	$ (4.6)	45.4	0.2	14.8
Pre-tax (loss) income from continuing operations	$ (66.8)	$ 20.0	$ (2.1)	$ 8.5	$ 246.3	$ (86.9)	$ (5.1)	$ 3.0	(40.4)	157.3	(29.4)
Tax Payments and Receipts
Net income tax payments to (receipts from) national governments, total									(12.8)	(6.5)	2.7
Non-US
Differences in taxes resulting from:
Pre-tax (loss) income from continuing operations									$ 16.3	$ 208.5	$ 60.4

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Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

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