Retirement Plans - Asset Allocations (Detail) - USD ($) $ in Millions		Dec. 30, 2023	Dec. 31, 2022		Jan. 01, 2022
Schedule Of Other Postretirement Benefits [Line Items]
Fair value of plan assets		$ 262.7	$ 251.4		$ 323.0
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage		100.00%	100.00%
Equity securities [Member]
Schedule Of Other Postretirement Benefits [Line Items]
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage		46.70%	44.70%
Equity securities [Member] | Fair Value Measured at Net Asset Value Per Share [Member]
Schedule Of Other Postretirement Benefits [Line Items]
Fair value of plan assets	[1]	$ 122.7	$ 112.2
Fixed income securities [Member]
Schedule Of Other Postretirement Benefits [Line Items]
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage		32.70%	35.80%
Fixed income securities [Member] | Fair Value Measured at Net Asset Value Per Share [Member]
Schedule Of Other Postretirement Benefits [Line Items]
Fair value of plan assets	[1]	$ 85.8	$ 90.0
Cash and Cash Equivalents
Schedule Of Other Postretirement Benefits [Line Items]
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage		19.90%	18.50%
Cash and Cash Equivalents | Fair Value Measured at Net Asset Value Per Share [Member]
Schedule Of Other Postretirement Benefits [Line Items]
Fair value of plan assets		$ 52.4	$ 46.6
Other Investments [Member]
Schedule Of Other Postretirement Benefits [Line Items]
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage		0.70%	1.00%
Other Investments [Member] | Fair Value, Inputs, Level 3 [Member]
Schedule Of Other Postretirement Benefits [Line Items]
Fair value of plan assets		$ 1.8	$ 2.6	[2]

[1] In accordance with ASC 820, Fair Value Measurement (“ASC 820”), certain investments are measured at fair value using the net asset value per share as a practical expedient. These assets have not been classified in the fair value hierarchy.

[2] In accordance with ASC 820, investments have been measured using valuation techniques in which one or more significant inputs are unobservable (Level 3). See Note 1 for additional information.