Benefit Plans, Pension Obligation and Funded Status (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Benefit Plans [Abstract]
Employee vesting period for defined benefit plans	5 years
Employer Contributions [Abstract]
Maximum percentage of total benefit obligation for international pension plans	25.00%
Change in plan assets [Roll Forward]
Beginning fair value	$ 289.3
Ending fair value	320.2	$ 289.3
Pension Benefits [Member]
Change in benefit obligations [Roll Forward]
Beginning projected benefit obligation	427.9	416.6
Service cost	7.9	8.2	$ 10.3
Interest cost	12.6	13.0	15.4
Actuarial (gain)/loss	31.5	21.2
Benefits paid	(20.4)	(18.3)
Settlements	0.0	(0.9)
Foreign exchange impact	9.6	(11.4)
Other	0.4	(0.5)
Ending projected benefit obligation	469.5	427.9	416.6
Change in plan assets [Roll Forward]
Beginning fair value	289.3	282.5
Actual return on plan assets	33.8	22.9
Employer contributions	10.7	10.5
Plan participants' contributions	0.4	0.4
Benefits paid	(20.4)	(18.3)
Settlements	(0.8)	(0.5)
Foreign exchange impact	7.2	(8.2)
Ending fair value	320.2	289.3	282.5
Funded status of the plan	(149.3)	(138.6)
Post-retirement Benefits [Member]
Change in benefit obligations [Roll Forward]
Beginning projected benefit obligation	9.3	9.3
Service cost	0.3	0.3	0.4
Interest cost	0.3	0.3	0.3
Actuarial (gain)/loss	(3.0)	(0.6)
Benefits paid	(0.1)	0.0
Settlements	0.0	0.0
Foreign exchange impact	0.1	0.0
Other	0.0	0.0
Ending projected benefit obligation	6.9	9.3	9.3
Change in plan assets [Roll Forward]
Beginning fair value	0.0	0.0
Actual return on plan assets	0.0	0.0
Employer contributions	0.1	0.0
Plan participants' contributions	0.0	0.0
Benefits paid	(0.1)	0.0
Settlements	0.0	0.0
Foreign exchange impact	0.0	0.0
Ending fair value	0.0	0.0	$ 0.0
Funded status of the plan	$ (6.9)	$ (9.3)