Pension Plans and Postretirement Benefits (Details) - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Sep. 27, 2015	Mar. 29, 2015	Sep. 28, 2014	Sep. 27, 2015	Sep. 28, 2014
Components of net period pension benefit expense
Pension plan curtailment		$ 1.2
Pension Benefits
Components of net period pension benefit expense
Service cost — benefits earned during the period	$ 3.3		$ 3.2	$ 10.0	$ 9.4
Interest cost on benefit obligation	9.9		10.6	29.6	31.9
Expected return on plan assets	(19.2)		(19.1)	(57.5)	(57.3)
Amortization of prior service cost	(1.5)		(1.2)	(4.5)	(3.5)
Amortization of net actuarial gains (losses)	8.5		6.2	25.5	18.5
Pension plan curtailment	0.0		0.0	(1.2)	0.0
Net expense (income)	1.0		(0.3)	1.9	(1.0)
Postretirement Benefits
Components of net period pension benefit expense
Interest cost on benefit obligation	0.1		0.2	0.4	0.5
Amortization of prior service cost	0.0		(0.1)	0.0	(0.2)
Amortization of net actuarial gains (losses)	0.0		(0.1)	(0.1)	(0.4)
Net expense (income)	$ 0.1		$ 0.0	$ 0.3	$ (0.1)