Restructuring Activities - Additional Information (Detail)			3 Months Ended					4 Months Ended		12 Months Ended
	Jul. 02, 2018 Segment	May 03, 2017 BusinessUnit	Jan. 02, 2021 USD ($)	Jul. 11, 2020 USD ($) Bakery	Dec. 28, 2019 USD ($)	Oct. 05, 2019 USD ($)	Jul. 13, 2019 USD ($)	Apr. 18, 2020 Bakery	Apr. 20, 2019 USD ($)	Jan. 01, 2022 USD ($) Segment	Jan. 02, 2021 USD ($) Bakery		Dec. 28, 2019 USD ($)
Restructuring Cost And Reserve [Line Items]
Number of operating segments | Segment										1
Project centennial costs										$ 0	$ 15,548,000	[1]	$ 784,000	[1]
Impairment charges assets held for sale			$ 1,300,000	$ 4,200,000							$ 23,627,000		21,062,000
Number of closed bakeries reclassified as held for sale | Bakery				3				2			3
Restructuring and related impairment charges										$ 0	$ 23,627,000		20,229,000
RIF
Restructuring Cost And Reserve [Line Items]
Employee severance charges recognized											5,300,000
Bakeries
Restructuring Cost And Reserve [Line Items]
Impairment charges assets held for sale				$ 5,700,000							5,700,000
Spare Parts
Restructuring Cost And Reserve [Line Items]
Impairment charges assets held for sale				700,000							700,000
Closed Plant | Opelika, Alabama
Restructuring Cost And Reserve [Line Items]
Impairment charges assets held for sale						$ 3,900,000	$ 1,300,000
Employee severance charges recognized						$ 1,500,000
Manufacturing Lines
Restructuring Cost And Reserve [Line Items]
Impairment charges assets held for sale									$ 400,000
Impairment of Trademark
Restructuring Cost And Reserve [Line Items]
Impairment charge			1,300,000	4,600,000
Lease Impairment Charges
Restructuring Cost And Reserve [Line Items]
Restructuring and related impairment charges											9,397,000
Lease Termination Charges
Restructuring Cost And Reserve [Line Items]
Restructuring and related impairment charges											4,077,000
Reorganization Costs
Restructuring Cost And Reserve [Line Items]
Restructuring and related impairment charges													$ 253,000
Develop Leading Capabilities
Restructuring Cost And Reserve [Line Items]
Number of operating segments | Segment	1
Line and Distribution Depot Closings
Restructuring Cost And Reserve [Line Items]
Impairment charges assets held for sale				$ 600,000
Employee Severance | Voluntary Employee Separation Incentive Plan
Restructuring Cost And Reserve [Line Items]
Employee termination benefits											$ 2,600,000
Launch of Project Centennial
Restructuring Cost And Reserve [Line Items]
Ingredient and packaging impairments			$ 1,200,000
Additional impairment charge on certain finite-lived intangible assets					$ 15,400,000
Launch of Project Centennial | Develop Leading Capabilities
Restructuring Cost And Reserve [Line Items]
Number of new organizational structure business units established | BusinessUnit		2

[1] Represents non-restructuring costs and are recorded in the selling, distribution, and administrative expenses line item of our Consolidated Statements of Income.