Retirement and Post Retirement Health Care Plans (Level 3 Plan Assets) (Details) $ in Millions	12 Months Ended
Jan. 02, 2021 USD ($)	Dec. 28, 2019 USD ($)
Change in Fair Value of Plan Assets:
Fair Value of Plan Assets at Beginning of Period	$ 203.4
Fair Value of Plan Assets at End of Period	230.2	$ 203.4
Level 3
Change in Fair Value of Plan Assets:
Fair Value of Plan Assets at Beginning of Period	9.9	10.3
Net Purchases (Sales)	0.0	(1.6)
Net Gains	0.1	1.2
Fair Value of Plan Assets at End of Period	10.0	9.9
Real Estate
Change in Fair Value of Plan Assets:
Fair Value	$ 10.0	$ 9.9
Exit Capitalization Rate
Change in Fair Value of Plan Assets:
Weighted Average	5.10%
Exit Capitalization Rate \| Real Estate \| Level 3 \| Minimum
Change in Fair Value of Plan Assets:
Measurement Input	0.045	0.050
Exit Capitalization Rate \| Real Estate \| Level 3 \| Maximum
Change in Fair Value of Plan Assets:
Measurement Input	0.070	0.070
Discount Rate
Change in Fair Value of Plan Assets:
Weighted Average	6.30%
Discount Rate \| Real Estate \| Level 3 \| Minimum
Change in Fair Value of Plan Assets:
Measurement Input	0.058	0.065
Discount Rate \| Real Estate \| Level 3 \| Maximum
Change in Fair Value of Plan Assets:
Measurement Input	0.085	0.080

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Amount of asset segregated and restricted to provide benefit under defined benefit plan. Asset includes, but is not limited to, stock, bond, other investment, earning from investment, and contribution by employer and employee.

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