Income Taxes Income Taxes - Unrecognized Tax Benefits (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Reconciliation of unrecognized tax benefits [Roll Forward]
Balance at January 1	$ 37.1	$ 32.6
Additions based on tax positions related to the current year	0.2	0.4
Additions for tax positions of prior years	6.1	0.0
Unrecognized Tax Benefits, Increase Resulting from Acquisition	0.0	5.9
Settlements	(5.0)	0.5
Reductions for tax positions of prior years	0.1	(0.7)
Lapse of statutes	(16.9)	(1.6)
Balance at December 31	$ 21.6	$ 37.1