Schedule of Employee Benefit Plans Components of Net Periodic Benefit Cost (Credit) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Pension Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	$ 0.4	$ 1.0	$ 0.7	$ 2.1
Interest cost	7.1	6.8	14.2	13.7
Expected asset return	(10.3)	(11.5)	(20.6)	(23.0)
Amortized loss	1.5	2.2	3.2	4.4
Amortized prior service cost (credit)	0.0	0.1	0.0	0.1
Curtailment	0.0	0.0	0.0	3.2
Net periodic benefit cost (credit)	(1.3)	(1.4)	(2.5)	0.5
Other Postretirement Benefits Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	0.1	0.1	0.2	0.2
Interest cost	3.2	3.1	6.4	6.2
Amortized loss	0.0	0.2	0.1	0.4
Amortized prior service cost (credit)	(0.4)	(0.6)	(0.8)	(1.3)
Net periodic benefit cost	$ 2.9	$ 2.8	$ 5.9	$ 5.5