Segment Information (Schedule Of Financial Information Attributable To Geographic Regions) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Jan. 02, 2021	Sep. 26, 2020	Jun. 27, 2020	Mar. 28, 2020	Dec. 28, 2019	Sep. 28, 2019	Jun. 29, 2019	Mar. 30, 2019	Jan. 02, 2021	Dec. 28, 2019	Dec. 29, 2018
Segment Reporting Information [Line Items]
Net Sales	$ 780.5	$ 758.2	$ 634.1	$ 734.2	$ 738.2	$ 772.3	$ 873.7	$ 853.8	$ 2,907.0	$ 3,238.0	$ 3,645.6
Long-lived assets	555.5				605.0				555.5	605.0
United States
Segment Reporting Information [Line Items]
Net Sales									1,885.1	2,071.9	2,402.9
Long-lived assets	200.5				237.6				200.5	237.6
Mexico
Segment Reporting Information [Line Items]
Long-lived assets	141.2				149.0				141.2	149.0
China
Segment Reporting Information [Line Items]
Long-lived assets	85.7				84.9				85.7	84.9
Rest of the World
Segment Reporting Information [Line Items]
Net Sales									1,021.9	1,166.1	$ 1,242.7
Long-lived assets	$ 128.1				$ 133.5				$ 128.1	$ 133.5