Restructuring Costs Restructuring Liability (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	$ 1.4	$ 7.7
Restructuring and Related Cost, Incurred Cost	1.4
Restructuring Costs, Paid or Settled	(7.7)
Restructuring Reserve	1.4
One-time Termination Benefits [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	1.2	1.2
Restructuring and Related Cost, Incurred Cost	1.0
Restructuring Costs, Paid or Settled	(1.0)
Restructuring Reserve	1.2
Lease Termination Costs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	0.0	0.0
Restructuring and Related Cost, Incurred Cost	0.0
Restructuring Costs, Paid or Settled	0.0
Restructuring Reserve	0.0
Accelerated Share Based Compensation [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	0.0	0.0
Restructuring and Related Cost, Incurred Cost	0.2
Restructuring Costs, Paid or Settled	(0.2)
Restructuring Reserve	0.0
Retention Expense [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	0.2	6.5
Restructuring and Related Cost, Incurred Cost	0.2
Restructuring Costs, Paid or Settled	(6.5)
Restructuring Reserve	0.2
Pension curtailment [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	0.0	$ 0.0
Restructuring and Related Cost, Incurred Cost	0.0
Restructuring Costs, Paid or Settled	0.0
Restructuring Reserve	$ 0.0