Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Oct. 01, 2017	Jul. 02, 2017	Apr. 02, 2017	Dec. 31, 2016	Oct. 02, 2016	Jul. 03, 2016	Apr. 03, 2016	Dec. 31, 2016
Changes in accumulated other comprehensive income (loss)
Balance at the beginning of the period				$ (150.8)
Reversal of foreign currency translation									$ 6.9
Balance at the end of the period	$ (99.1)				$ (150.8)				(150.8)
Foreign Currency Translation
Changes in accumulated other comprehensive income (loss)
Balance at the beginning of the period	(108.9)	$ (124.3)	$ (145.8)	(153.7)	(119.6)	$ (122.9)	$ (103.8)	$ (128.2)	(128.2)
Change in period	6.3	15.4	21.5	7.9	(34.1)	3.3	(19.1)	24.4
Balance at the end of the period	(102.6)	(108.9)	(124.3)	(145.8)	(153.7)	(119.6)	(122.9)	(103.8)	(153.7)
Cash Flow Hedges
Changes in accumulated other comprehensive income (loss)
Balance at the beginning of the period	2.4	2.3	3.0	2.9	(0.6)	(1.9)	(0.2)
Change in period	1.1	0.1	(0.7)	0.1	3.5	1.3	(1.7)	(0.2)
Balance at the end of the period	3.5	2.4	2.3	3.0	2.9	(0.6)	(1.9)	(0.2)	2.9
Accumulated Other Comprehensive Income (Loss)
Changes in accumulated other comprehensive income (loss)
Balance at the beginning of the period	(106.5)	(122.0)	(142.8)	(150.8)	(120.2)	(124.8)	(104.0)	(128.2)	(128.2)
Change in period	7.4	15.5	20.8	8.0	(30.6)	4.6	(20.8)	24.2
Balance at the end of the period	$ (99.1)	$ (106.5)	$ (122.0)	$ (142.8)	$ (150.8)	$ (120.2)	$ (124.8)	$ (104.0)	$ (150.8)