Restructuring Charges (Charges and Changes to Restructuring)(Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Restructuring Reserve [Roll Forward]
Restructuring liability, beginning balance			$ 1.2
Charges	$ 8.0	$ 2.4	27.4	$ 2.4
Cash Payments			(18.5)
Other			(0.4)
Restructuring liability, ending balance	9.7		9.7
Severance [Member]
Restructuring Reserve [Roll Forward]
Restructuring liability, beginning balance			0.7
Charges			25.4
Cash Payments			(18.3)
Other			(0.5)
Restructuring liability, ending balance	7.3		7.3
Severance [Member] | 2017 Restructuring Plan [Member]
Restructuring Reserve [Roll Forward]
Charges	6.6		25.4
Contract terminations and other [Member]
Restructuring Reserve [Roll Forward]
Restructuring liability, beginning balance			0.5
Charges			2.0
Cash Payments			(0.2)
Other			0.1
Restructuring liability, ending balance	2.4		2.4
Contract terminations and other [Member] | 2017 Restructuring Plan [Member]
Restructuring Reserve [Roll Forward]
Charges	$ 1.4		$ 2.0