Debt And Credit Facilities - Interest Expense (Details) - Convertible Debt - 2.375% convertible senior notes - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jul. 02, 2021	Jul. 03, 2020	Jul. 02, 2021	Jul. 03, 2020
Debt Instrument [Line Items]
Contractual interest expense	$ 3.0	$ 1.4	$ 6.1	$ 1.4
Amortization of debt issuance costs	0.4	0.2	0.9	0.2
Amortization of debt discount	4.7	2.0	9.3	2.0
Total interest expense	$ 8.1	$ 3.6	$ 16.3	$ 3.6

Amount of noncash expense included in interest expense to amortize debt discount and premium associated with the related debt instruments. Excludes amortization of financing costs. Alternate captions include noncash interest expense.

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Amount of amortization expense attributable to debt issuance costs.

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Amount of the cost of borrowed funds accounted for as interest expense for debt.

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