Schedule of Effect of Derivative Instruments in Statement of Operations Recognized (Parenthetical) (Detail) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jul. 01, 2018	Jul. 02, 2017	Jul. 01, 2018	Jul. 02, 2017
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) on foreign currency transactions	$ 1.9	$ 2.4	$ 2.5	$ 0.9

Amount before tax of foreign currency transaction unrealized gain (loss) recognized in the income statement.

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