Pension Plans and Other Postretirement Benefit Plans - Components of Net Periodic Benefit Cost (Income) (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
	Apr. 06, 2018	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Defined contribution retirement plan
Contributions by employer	$ 50.0			$ 50.0
Percentage that the employer contributes of employee contributions under 401(k) plan				100.00%
Maximum percentage of employee compensation match by employer to defined contribution plan				6.00%
Costs related to defined contribution retirement plan		$ 3.3	$ 2.8	$ 9.4	$ 8.5
United States
Net Periodic Benefit Cost
Service cost		4.9	4.3	14.6	12.9
Interest cost		10.3	10.5	30.9	31.5
Expected return on plan assets		(14.5)	(14.4)	(43.6)	(43.2)
Amortization of prior service credit		(0.2)	(0.1)	(0.5)	(0.3)
Net periodic benefit cost (income)		0.5	0.3	1.4	0.9
Non-U.S.
Net Periodic Benefit Cost
Service cost		2.3	2.2	7.2	6.2
Interest cost		1.3	1.1	3.8	3.2
Expected return on plan assets		(0.3)	(0.2)	(0.8)	(0.6)
Amortization of prior service credit		0.0	0.0	0.0	0.0
Net periodic benefit cost (income)		$ 3.3	$ 3.1	$ 10.2	$ 8.8