Employee Stock Benefit Plans (Components of Stock-based Compensation Expense) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 28, 2018	Dec. 29, 2017		Dec. 30, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	$ 76.9	$ 64.8	[1]	$ 52.6	[1]
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	68.9	53.3		35.9
Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	1.5	5.7		10.9
Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	$ 6.5	$ 5.8		$ 5.8

[1] See Note 2 for a summary of adjustments