Income Taxes (Unrecognized Tax Benefits Reconciliation) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Gross unrecognized tax benefits at beginning of year	$ 61.5	$ 55.6	$ 57.3
Increases in unrecognized tax benefits related to the current year	3.1	25.5	4.4
Increases in unrecognized tax benefits related to prior years	9.5	0.0	0.0
Decreases in unrecognized tax benefits related to a prior year	0.0	(17.5)	(0.2)
Unrecognized Tax Benefits, Decrease Resulting from Settlements with Taxing Authorities	(3.8)	0.0	(1.9)
Unrecognized Tax Benefits, Reduction Resulting from Lapse of Applicable Statute of Limitations	(22.2)	(2.1)	(4.0)
Gross unrecognized tax benefits at end of year	48.1	61.5	55.6
Liability for unrecognized tax benefits	51.0	64.9
Unrecognized tax benefits that if recognized would impact effective tax rate	30.6	19.6
Unrecognized tax benefits that would impact deferred tax asset	20.4	45.3
Unrecognized tax benefits, interest recorded	0.1	(1.9)	(0.3)
Unrecognized tax benefits, interest accruals	$ 1.6	$ 1.8	$ 3.7