Shareholders' Equity (Narrative) (Detail) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 30, 2018	Nov. 30, 2017
Two Thousand Seventeen Stock Repurchase Program [Member]
Equity, Class of Stock [Line Items]
Stock repurchase program approved amount		$ 600.0
Stock Repurchase Program, Remaining Authorized Repurchase Amount	$ 392.2
Retained Earnings [Member]
Equity, Class of Stock [Line Items]
Stock Repurchased During Period, Value	$ 42.5
Open Market Purchases [Member] | Two Thousand Seventeen Stock Repurchase Program [Member]
Equity, Class of Stock [Line Items]
Stock Repurchased During Period, Shares	1.3
Accelerated Share Repurchases, Final Price Paid Per Share	$ 39.43
Stock Repurchased During Period, Value	$ 50.0