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Shareholders' Equity (Narrative) (Detail) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended						9 Months Ended
	Sep. 27, 2019	Jun. 28, 2019	Mar. 29, 2019	Sep. 28, 2018	Jun. 29, 2018	Mar. 30, 2018	Sep. 27, 2019	Nov. 30, 2017
Equity, Class of Stock [Line Items]
Stock Repurchased During Period, Value	$ 120.8	$ 19.0	$ 40.0	$ 0.0	$ 0.0	$ 50.0
Two Thousand Seventeen Stock Repurchase Program [Member]
Equity, Class of Stock [Line Items]
Stock Repurchase Program, Remaining Authorized Repurchase Amount	172.4						$ 172.4
Retained Earnings [Member]
Equity, Class of Stock [Line Items]
Stock Repurchased During Period, Value	$ 99.5	$ 16.1	$ 33.5	$ 0.0	$ 0.0	$ 42.5	$ 149.1
Maximum \| Two Thousand Seventeen Stock Repurchase Program [Member]
Equity, Class of Stock [Line Items]
Stock repurchase program approved amount								$ 600.0
Open Market Purchases [Member] \| Two Thousand Seventeen Stock Repurchase Program [Member]
Equity, Class of Stock [Line Items]
Stock Repurchased During Period, Shares	3.3						4.7
Accelerated Share Repurchases, Final Price Paid Per Share	$ 37.57						$ 38.51
Stock Repurchased During Period, Value	$ 120.8						$ 179.8