Restructuring Charges (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended		15 Months Ended
	Oct. 01, 2016	Sep. 26, 2015	Oct. 01, 2016	Sep. 26, 2015	Oct. 01, 2016
Restructuring Reserve [Roll Forward]
Beginning balance	$ 12.2	$ 1.7	$ 20.7	$ 3.2	$ 1.7
Additional charges	6.6	2.2	17.9	3.1
Payments	(8.6)	(1.9)	(33.3)	(4.5)
Non-cash adjustments	0.1	(0.7)	5.0	(0.5)
Ending balance	$ 10.3	$ 1.3	$ 10.3	$ 1.3	10.3
Employee severance
Restructuring Cost and Reserve [Line Items]
Business exit costs					5.1
Lease exit
Restructuring Cost and Reserve [Line Items]
Business exit costs					$ 5.2