Pension Plans Narrative (Details) - Foreign Pension Plan [Member] - USD ($) $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2017	Jul. 01, 2016	Jun. 30, 2017	Jul. 01, 2016	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 1.0	$ 0.9	$ 2.0	$ 1.7
Interest cost	1.5	1.9	2.9	3.8
Expected return on plan assets	(1.8)	(2.1)	(3.6)	(4.1)
Amortization of net loss	1.1	1.5	2.2	2.8
Net periodic pension cost	$ 1.8	$ 2.2	$ 3.5	$ 4.2
Scenario, Forecast [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected contributions					$ 10.0