Restructuring Restructuring (Details) - 2015 Restructuring Charges - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2017	Dec. 31, 2016
Restructuring Cost and Reserve [Line Items]
Restructuring reserve, beginning period		$ 5.1	$ 37.3
Expense			10.3
Payments		(4.6)	(40.2)
Adjustments to previous estimates, net	$ 15.9		(2.3)
Restructuring reserve, ending period	37.3	0.5	5.1
Workforce reduction
Restructuring Cost and Reserve [Line Items]
Restructuring reserve, beginning period		2.2	33.7
Expense			4.9
Payments		(1.7)	(31.2)
Adjustments to previous estimates, net			(5.2)
Restructuring reserve, ending period	33.7	0.5	2.2
Pipeline programs
Restructuring Cost and Reserve [Line Items]
Restructuring reserve, beginning period		2.9	3.6
Expense			5.4
Payments		(2.9)	(9.0)
Adjustments to previous estimates, net			2.9
Restructuring reserve, ending period	$ 3.6	$ 0.0	$ 2.9