Postretirement Benefits (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017
Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest Cost	$ 5.7	$ 7.1	$ 11.4	$ 14.2
Expected Return on Plan Assets	(6.4)	(8.3)	(12.7)	(16.7)
Amortization of Prior Service Credits	0.0	0.0	0.0	0.0
Amortization of Net Actuarial Losses	2.6	3.6	5.1	7.2
Net Pension and Other Benefit Costs	1.9	2.4	3.8	4.7
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest Cost	0.2	0.4	0.5	0.7
Expected Return on Plan Assets	0.0	0.0	0.0	0.0
Amortization of Prior Service Credits	(0.1)	(0.2)	(0.3)	(0.4)
Amortization of Net Actuarial Losses	0.0	0.0	0.0	0.0
Net Pension and Other Benefit Costs	$ 0.1	$ 0.2	0.2	0.3
Nonqualified Plan [Member] | Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Contributions By Employer For Nonqualified Pension Plan			2.1	2.1
Qualified Plan [Member] | Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Contributions By Employer For Nonqualified Pension Plan			$ 35.0	$ 40.0