Fair Value Measurements (Additional Fair Value Information Relating To Company's Financial Instruments Outstanding) (Detail) - USD ($) $ in Millions	Mar. 30, 2018	Dec. 29, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt	$ 1,122.3	$ 913.9
Senior Notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notes Payable, Noncurrent	400.0	400.0
Note Payable Fair Value	418.5	430.4
Uncommitted Facilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt	130.0	128.0
Long-term Debt, Fair Value	130.0	128.0
Promissory Notes And Other Debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notes Payable, Noncurrent	0.9	0.8
Note Payable Fair Value	1.4	1.2
Total debt	1.4	1.2
Two Thousand Fourteen Credit Facility [Member] | Revolving Credit Facility [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt	295.0	389.0
Line of Credit Facility, Fair Value of Amount Outstanding	295.0	$ 389.0
Two Thousand Eighteen Interim Credit Facilities [Member] | Revolving Credit Facility [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Line of Credit Facility, Fair Value of Amount Outstanding	300.0
Short-term Debt	$ 300.0