Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2019	Sep. 29, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jul. 01, 2018	Apr. 01, 2018
Changes in accumulated other comprehensive income (loss)
Balance at the beginning of the period				$ (121.1)
Balance at the end of the period	$ (130.8)				$ (121.1)
Foreign Currency Translation
Changes in accumulated other comprehensive income (loss)
Balance at the beginning of the period	(143.2)	$ (127.4)	$ (130.9)	(126.3)	(117.0)	$ (119.5)	$ (92.9)	$ (102.6)
Change in period	11.9	(15.8)	3.5	(4.6)	(9.3)	2.5	(26.6)	9.7
Balance at the end of the period	(131.3)	(143.2)	(127.4)	(130.9)	(126.3)	(117.0)	(119.5)	(92.9)
Cash Flow Hedges
Changes in accumulated other comprehensive income (loss)
Balance at the beginning of the period	1.0	1.5	3.9	5.2	7.2	7.3	6.3	3.5
Change in period	(0.5)	(0.5)	(2.4)	(1.3)	(2.0)	(0.1)	1.0	2.8
Balance at the end of the period	0.5	1.0	1.5	3.9	5.2	7.2	7.3	6.3
Accumulated Other Comprehensive Income (Loss)
Changes in accumulated other comprehensive income (loss)
Balance at the beginning of the period	(142.2)	(125.9)	(127.0)	(121.1)	(109.8)	(112.2)	(86.6)	(99.1)
Change in period	11.4	(16.3)	1.1	(5.9)	(11.3)	2.4	(25.6)	12.5
Balance at the end of the period	$ (130.8)	$ (142.2)	$ (125.9)	$ (127.0)	$ (121.1)	$ (109.8)	$ (112.2)	$ (86.6)