Pension Plans and Postretirement Benefits (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 29, 2015	Jan. 01, 2017	Jan. 03, 2016	Dec. 28, 2014	Dec. 29, 2013
Defined Benefit Plan Disclosure [Line Items]
Net periodic pension expense			$ 2.0	$ 1.7	$ 16.6
Curtailment	$ 1.2
Amount recoverable from government contract due to US government cost accounting standards			13.8	13.8	14.5
Pretax contribution					83.0
Employer contributions to 401(k) plans			10.1	9.5	9.1
Non-cash reduction to stockholders' equity			232.3	227.3
Deferred tax on non-cash reductions to stockholders' equity			$ 3.0	56.2
Assumed rate of increase in the per capita cost of covered benefits			7.00%
Ultimate health care cost trend rate, 2020 and thereafter			5.00%
Effect of one percentage point increase in assumed health care cost trend rates on annual service and interest costs			$ 0.1
Effect of one percentage point increase in assumed health care cost trend rates on postretirement benefit obligation			0.4
Effect of one percentage point decrease in assumed health care cost trend rates on annual service and interest costs			0.1
Effect of one percentage point decrease in assumed health care cost trend rates on postretirement benefit obligation			0.3
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit cost expected to be recognized for the pension plans, net gain (loss)			27.2
Net periodic benefit cost expected to be recognized for the pension plans, net prior service credit			$ 6.1
Pension Benefits Domestic Plans
Defined Benefit Plan Disclosure [Line Items]
Percentage of employees under defined benefit pension plan			18.00%
Net periodic pension expense			$ 2.0	(1.7)	16.6
Curtailment			(1.2)	0.0	$ 0.0
Settlements			$ 10.5	$ 32.4
Expected weighted-average long-term rate of return			8.25%	8.25%	8.25%
Unrecognized net (gain) loss			$ 398.6	$ 379.6
Unrecognized prior service credit			36.7	27.0
Pension Benefits Foreign Plans
Defined Benefit Plan Disclosure [Line Items]
Net periodic pension expense			1.0	0.4	$ 0.9
Curtailment			0.0	0.0	0.0
Unrecognized net (gain) loss			13.0	12.9
Unrecognized prior service credit			0.3	0.1
Postretirement Plans
Defined Benefit Plan Disclosure [Line Items]
Net periodic pension expense			0.3	(0.1)	$ (0.2)
Net periodic benefit cost expected to be recognized for the pension plans, net gain (loss)			0.3
Net periodic benefit cost expected to be recognized for the pension plans, net prior service credit			0.1
Unrecognized net (gain) loss			(4.2)	$ (3.1)
Unrecognized prior service credit			$ 0.1
Equity instruments | Pension Benefits Domestic Plans
Defined Benefit Plan Disclosure [Line Items]
Target allocation of plan assets			70.00%
Target allocation of plan assets, minimum			45.00%
Target allocation of plan assets, maximum			75.00%
Equity instruments | Pension Benefits Foreign Plans
Defined Benefit Plan Disclosure [Line Items]
Target allocation of plan assets			60.00%
Fixed income instruments | Pension Benefits Domestic Plans
Defined Benefit Plan Disclosure [Line Items]
Target allocation of plan assets			30.00%
Debt Securities and Other | Pension Benefits Foreign Plans
Defined Benefit Plan Disclosure [Line Items]
Target allocation of plan assets			40.00%
Scenario, Forecast | Pension Benefits Domestic Plans
Defined Benefit Plan Disclosure [Line Items]
Expected weighted-average long-term rate of return		8.00%
Minimum | Pension Benefits Foreign Plans
Defined Benefit Plan Disclosure [Line Items]
Expected weighted-average long-term rate of return			1.80%	3.00%	3.00%
Minimum | Scenario, Forecast | Pension Benefits Foreign Plans
Defined Benefit Plan Disclosure [Line Items]
Expected weighted-average long-term rate of return		1.40%
Maximum | Pension Benefits Foreign Plans
Defined Benefit Plan Disclosure [Line Items]
Expected weighted-average long-term rate of return			6.40%	6.40%	5.50%
Maximum | Scenario, Forecast | Pension Benefits Foreign Plans
Defined Benefit Plan Disclosure [Line Items]
Expected weighted-average long-term rate of return		6.50%