Pension Plans - Components of Net Periodic Pension Cost (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 25, 2020	Sep. 27, 2019	Sep. 25, 2020	Sep. 27, 2019
United states
Defined Benefit Plan Disclosure [Line Items]
Interest cost	$ 0.4	$ 0.4	$ 1.0	$ 1.2
Expected return on plan assets	(0.4)	(0.3)	(1.0)	(1.0)
Amortization of net loss	0.0	0.0	0.2	0.0
Net periodic pension cost	0.0	0.1	0.2	0.2
Non-U.S.
Defined Benefit Plan Disclosure [Line Items]
Service cost	1.2	0.7	3.4	1.7
Interest cost	1.1	1.4	3.1	4.3
Expected return on plan assets	(1.4)	(1.5)	(4.2)	(4.4)
Amortization of net loss	1.1	0.7	3.2	2.1
Amortization of prior service cost	0.0	0.0	0.2	0.0
Net periodic pension cost	$ 2.0	$ 1.3	$ 5.7	$ 3.7