Pension and Other Postretirement Benefits (Details 2) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Mar. 30, 2012
Pension Plans
Net periodic benefit cost and other amounts recognized in accumulated other comprehensive loss:
Service cost for benefits earned during the period	$ 3.2	$ 3.0
Interest cost on projected benefit obligation	8.6	9.1
Expected return on plan assets	(8.6)	(8.7)
Amortization of actuarial loss	2.6	1.5
Net periodic benefit cost	5.8	4.9
Benefit obligation and fair value of plan assets by pension plans
Consolidated pension funding contributions for 2012	20.0		1.2
Retiree Medical
Net periodic benefit cost and other amounts recognized in accumulated other comprehensive loss:
Service cost for benefits earned during the period	0.8	0.7
Interest cost on projected benefit obligation	1.0	1.0
Amortization of transition obligation	0.1	0.1
Amortization of actuarial loss	0.3	0.2
Net periodic benefit cost	$ 2.2	$ 2.0