Other Income (Expense), Net and Gain on Sale of Product Lines (Narrative) (Details) - USD ($) $ / shares in Units, $ in Millions		3 Months Ended		6 Months Ended		12 Months Ended
	Apr. 30, 2020	Jul. 03, 2020	Jun. 28, 2019	Jul. 03, 2020	Jun. 28, 2019	Dec. 31, 2019
Other Income and Expenses [Abstract]
Other nonoperating income, net pension and postretirement benefits		$ 5.0	$ 5.0	$ 10.0	$ 10.0
Unrealized loss on investments		$ (6.0)		$ (13.0)
Unrealized loss on investments, per diluted common share		$ (0.01)		$ (0.02)
Disposal group, product lines, revenues						$ 170.0
Proceeds from sale of product lines	$ 810.0			$ 809.8	0.0
Pretax gain on sale of product lines		$ 454.6	$ 0.0	454.6	$ 0.0
Gain on sale of product lines, net of tax		$ 305.0		$ 305.0
Gain on sale of product lines, net of tax, per diluted common share		$ 0.42		$ 0.42