Comprehensive Income (Components Of Accumulated Other Comprehensive Income, Net Of Related Tax) (Details) - USD ($) $ in Millions	Dec. 28, 2018	Dec. 29, 2017
Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
Accumulated foreign currency translation adjustments	$ (183.4)	$ (127.8)
Net unrealized loss on short-term investments	0.0	(0.2)
Net unrealized actuarial losses	(2.7)	(3.4)
Total accumulated other comprehensive income	$ (186.1)	$ (131.4)	[1]

[1] See Note 2 for a summary of adjustments