Benefit Plans (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Defined Benefit Plan Disclosure [Line Items]
Document Period End Date			Jun. 30, 2018
Components of net periodic benefit cost
Contributions to qualified and non qualified pension plans			$ 25.1	$ 13.6
Other Postretirement Benefits Plan [Member]
Components of net periodic benefit cost
Service cost	$ 0.0	$ 0.0	0.0	0.0
Interest cost	0.1	0.1	0.2	0.2
Expected return on plan assets	0.0	0.0	0.0	0.0
Recognized net actuarial loss	0.0	0.0	0.0	0.0
Net periodic pension benefit cost	0.1	0.1	0.2	0.2
Domestic Plan [Member] | Pension Plan [Member]
Components of net periodic benefit cost
Service cost	0.9	1.0	1.9	2.0
Interest cost	5.1	5.7	10.3	11.4
Expected return on plan assets	(6.1)	(6.5)	(12.3)	(13.0)
Recognized net actuarial loss	1.7	1.5	3.3	3.0
Net periodic pension benefit cost	1.6	1.7	3.2	3.4
Foreign Plan [Member] | Pension Plan [Member]
Components of net periodic benefit cost
Service cost	2.8	2.6	5.6	5.2
Interest cost	1.6	2.2	3.2	4.4
Expected return on plan assets	(2.7)	(2.1)	(5.4)	(4.2)
Recognized net actuarial loss	(0.1)	(0.1)	(0.3)	(0.2)
Net periodic pension benefit cost	$ 1.6	$ 2.6	$ 3.1	$ 5.2