Fair Value Measurements (Assets And Liabilities Measured At Fair Value On Recurring Basis) (Detail) - Recurring - USD ($) $ in Millions	Apr. 02, 2021	Jan. 01, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Deferred compensation plan assets	$ 42.7	$ 41.9
Derivatives assets	0.2	0.9
Total assets measured at fair value	42.9	42.8
Deferred compensation plan liabilities	42.7	41.9
Derivatives liabilities	0.3	0.5
Contingent consideration liabilities	13.6	12.3
Total liabilities measured at fair value	56.6	54.7
(Level I)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Deferred compensation plan assets	42.7	41.9
Derivatives assets	0.0	0.0
Total assets measured at fair value	42.7	41.9
Deferred compensation plan liabilities	42.7	41.9
Derivatives liabilities	0.0	0.0
Contingent consideration liabilities	0.0	0.0
Total liabilities measured at fair value	42.7	41.9
(Level II)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Deferred compensation plan assets	0.0	0.0
Derivatives assets	0.2	0.9
Total assets measured at fair value	0.2	0.9
Deferred compensation plan liabilities	0.0	0.0
Derivatives liabilities	0.3	0.5
Contingent consideration liabilities	0.0	0.0
Total liabilities measured at fair value	0.3	0.5
(Level III)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Deferred compensation plan assets	0.0	0.0
Derivatives assets	0.0	0.0
Total assets measured at fair value	0.0	0.0
Deferred compensation plan liabilities	0.0	0.0
Derivatives liabilities	0.0	0.0
Contingent consideration liabilities	13.6	12.3
Total liabilities measured at fair value	$ 13.6	$ 12.3