Stock Plans (Summary of Stock Option Activity) (Details) $ / shares in Units, shares in Thousands, $ in Millions	6 Months Ended
	Jul. 02, 2017 USD ($) $ / shares shares
Stock option activity
Number of Shares, Outstanding at beginning of period | shares	2,287
Number of Shares, Granted | shares	451
Number of Shares, Exercised | shares	(432)
Number of Shares, Forfeited | shares	(6)
Number of Shares, Outstanding at end of period | shares	2,300
Number of Shares, Exercisable at end of period | shares	1,359
Weighted-Average Price, Outstanding at beginning of period | $ / shares	$ 37.64
Weighted-Average Price, Granted | $ / shares	53.54
Weighted-Average Price, Exercised | $ / shares	30.64
Weighted-Average Price, Forfeited | $ / shares	50.48
Weighted-Average Price, Outstanding at end of period | $ / shares	42.04
Weighted-Average Price, Exercisable at end of period | $ / shares	$ 37.09
Weighted-Average Remaining Contractual Term in Years, Outstanding at end of period	4 years 3 months
Weighted-Average Remaining Contractual Term in Years, Exercisable at end of period	3 years 2 months
Total Intrinsic Value, Outstanding at end of period | $	$ 46.2
Total Intrinsic Value, Exercisable at end of period | $	$ 34.0