Debt (Schedule Of Debt) (Details) - USD ($) $ in Millions	Dec. 31, 2021	Jan. 01, 2021
Debt Instrument [Line Items]
Debt gross	$ 0.0
Unamortized discount and issuance costs	(6.8)	$ (8.7)
Total	1,293.2	1,547.2
Less: Short-term debt	0.0	255.8
Total debt	1,293.2	1,291.4
Promissory Notes and Other
Debt Instrument [Line Items]
Long-term debt, gross	0.0	0.1
Uncommitted Facilities
Debt Instrument [Line Items]
Debt gross	$ 0.0	255.8
Two Thousand Twenty Three Senior Notes | Senior Notes
Debt Instrument [Line Items]
Long-term debt, percentage bearing fixed interest, percentage rate	4.15%
Effective Interest Rate	4.36%
Long-term debt, gross	$ 300.0	300.0
Two Thousand Twenty Eight Senior Notes | Senior Notes
Debt Instrument [Line Items]
Long-term debt, percentage bearing fixed interest, percentage rate	4.90%
Effective Interest Rate	5.04%
Long-term debt, gross	$ 600.0	600.0
Two Thousand Twenty Four Senior Notes | Senior Notes
Debt Instrument [Line Items]
Long-term debt, percentage bearing fixed interest, percentage rate	4.75%
Effective Interest Rate	4.95%
Long-term debt, gross	$ 400.0	$ 400.0