Reporting Segment And Geographic Information (Schedule Of Long-Lived Assets) (Details) - USD ($) $ in Millions	Dec. 31, 2021	Jan. 01, 2021
Revenues from External Customers and Long-Lived Assets [Line Items]
Property and equipment, net	$ 233.2	$ 251.8
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Property and equipment, net	171.3	200.3
Europe
Revenues from External Customers and Long-Lived Assets [Line Items]
Property and equipment, net	44.8	41.0
Asia Pacific and Rest of World
Revenues from External Customers and Long-Lived Assets [Line Items]
Property and equipment, net	$ 17.1	$ 10.5