Summary Of Significant Accounting Policies - Additional Information (Detail)				3 Months Ended									4 Months Ended			12 Months Ended
	Mar. 09, 2021 USD ($)	Sep. 28, 2016 USD ($)	Apr. 03, 2012 USD ($)	Jan. 01, 2022 USD ($)	Oct. 09, 2021 USD ($)	Jul. 17, 2021 USD ($)	Jan. 02, 2021 USD ($)	Oct. 03, 2020 USD ($)	Jul. 11, 2020 USD ($) Bakery	Jul. 11, 2020 USD ($)	Oct. 05, 2019 USD ($)	Jul. 13, 2019 USD ($)	Apr. 24, 2021 USD ($)	Apr. 18, 2020 USD ($) Bakery	Apr. 20, 2019 USD ($)	Jan. 01, 2022 USD ($) Segment	Jan. 02, 2021 USD ($) Bakery	Dec. 28, 2019 USD ($)	Dec. 29, 2018 USD ($)
Significant Accounting Policies [Line Items]
Sales				$ 983,490,000	$ 1,027,800,000	$ 1,017,309,000	$ 1,023,036,000	$ 989,650,000		$ 1,025,861,000			$ 1,302,168,000	$ 1,349,444,000		$ 4,330,767,000	$ 4,387,991,000	$ 4,123,974,000
Deferred gain on sale of assets held for sale				19,700,000			23,900,000									19,700,000	23,900,000
Net gain on sale of distribution rights																1,600,000	5,100,000	4,100,000
Loss of repurchase obligations of distribution rights related to a legal settlement																4,700,000
Capitalized interest				0			0									$ 0	0	0
Increase to assets																			$ 387,300,000
Increase to liabilities																			$ 391,900,000
Lessee, operating lease, existence of residual value guarantees																false
Lessee, operating lease, residual value guarantees, description																Additionally, these contracts do not contain residual value guarantees, and there are no other restrictions or covenants in the contracts.
Financing ROU assets				3,476,000			5,419,000									$ 3,476,000	5,419,000
Financing right-of-use lease liabilities				3,494,000												3,494,000
Gain on termination of embedded leases																$ (41,610,000)	(14,817,000)
Number of operating segments | Segment																1
Restructuring and related impairment charges																$ 0	$ 23,627,000	20,229,000
Number of closed bakeries reclassified as held for sale | Bakery									3					2			3
Impairment charges assets held for sale							1,300,000		$ 4,200,000								$ 23,627,000	$ 21,062,000
Proceeds from sale of assets held for sale																2,200,000
Gain at time of sale							(1,400,000)									900,000
Finite-lived intangible asset amortization periods																		33 years
Goodwill impairment loss																0	0	$ 0
Advertising and marketing costs																77,700,000	60,400,000	48,200,000
Capitalized software development costs				21,100,000			21,900,000									21,100,000	21,900,000
Amortization expense of capitalized software development costs																9,900,000	9,300,000	10,200,000
Debt instrument face amount				900,000,000			800,000,000									900,000,000	800,000,000
Research and development costs																5,600,000	4,000,000.0	4,300,000
Consulting costs related to transformation strategy																31,300,000
Consulting costs related to ERP road mapping								$ 4,400,000
2031 Notes
Significant Accounting Policies [Line Items]
Debt instrument face amount	$ 500,000,000.0			500,000,000												500,000,000
Debt instrument discount and issuance cost amortization period	10 years
2026 Notes
Significant Accounting Policies [Line Items]
Debt instrument face amount		$ 400,000,000.0		400,000,000			400,000,000									400,000,000	400,000,000
Debt instrument discount and issuance cost amortization period		10 years
4.375% Senior Notes Due 2022
Significant Accounting Policies [Line Items]
Debt instrument face amount			$ 400,000,000.0	400,000,000.0			400,000,000									$ 400,000,000.0	400,000,000
Debt instrument discount and issuance cost amortization period			10 years
Trademarks
Significant Accounting Policies [Line Items]
Restructuring impairment charges of indefinite intangible assets																		15,400,000
Impairment of Trademark
Significant Accounting Policies [Line Items]
Impairment charge							1,300,000		4,600,000
Bakeries
Significant Accounting Policies [Line Items]
Impairment charges assets held for sale									5,700,000								5,700,000
Line Closures and Office Building
Significant Accounting Policies [Line Items]
Impairment charges assets held for sale																	600,000
Spare Parts
Significant Accounting Policies [Line Items]
Impairment charges assets held for sale									$ 700,000								700,000
Manufacturing Lines
Significant Accounting Policies [Line Items]
Impairment charges assets held for sale															$ 400,000
Closed Plant
Significant Accounting Policies [Line Items]
Proceeds from sale of assets held for sale											$ 1,900,000
Gain at time of sale											800,000
Closed Plant | Winston-Salem, North Carolina
Significant Accounting Policies [Line Items]
Impairment charges assets held for sale												$ 1,300,000
Additional impairment charge of spare parts write-offs											200,000
Closed Plant | Opelika, Alabama
Significant Accounting Policies [Line Items]
Impairment charges assets held for sale											$ 3,900,000	$ 1,300,000
Bakery Equipment
Significant Accounting Policies [Line Items]
Lessee, operating lease term																less than a year up to seven years
Transportation Equipment
Significant Accounting Policies [Line Items]
Lessee, operating lease term																less than one year up to seven years
IT Equipment
Significant Accounting Policies [Line Items]
Lessee, operating lease term																less than a year up to five years
Certain Equipment and IT Equipment
Significant Accounting Policies [Line Items]
Lessee, operating lease term																shorter than a year
Buildings and Land
Significant Accounting Policies [Line Items]
Lessee, operating lease, existence of residual value guarantees																false
Lessee, operating lease, residual value guarantees, description																Additionally, these contracts do not contain residual value guarantees, and there are no other restrictions or covenants in the contracts.
Short Term Leases
Significant Accounting Policies [Line Items]
Lessee, operating lease, existence of residual value guarantees																false
Lessee, operating lease, residual value guarantees, description																do not contain residual value guarantees, and there are no other restrictions or covenants in the leases.
Lessee, operating lease, purchase options																false
Lessee, operating lease, option to extend, description																There are no purchase options present, however, there generally are renewals that could extend lease terms for additional periods.
Embedded Financing Truck And Trailer Leases
Significant Accounting Policies [Line Items]
Financing ROU assets							0										0
Financing right-of-use lease liabilities							0										0
Gain on termination of embedded leases																	4,100,000
Embedded Financing I T Equipment
Significant Accounting Policies [Line Items]
Financing ROU assets				3,000,000.0			4,600,000									$ 3,000,000.0	4,600,000
Financing right-of-use lease liabilities				$ 3,000,000.0			$ 4,600,000									$ 3,000,000.0	4,600,000
Minimum
Significant Accounting Policies [Line Items]
Lessee, operating lease term				1 year												1 year
Lessee, operating lease renewal term				1 month												1 month
Finite-lived intangible asset amortization periods																2 years
Minimum | Trademarks
Significant Accounting Policies [Line Items]
Finite-lived intangible asset amortization periods																5 years
Minimum | Short Term Leases
Significant Accounting Policies [Line Items]
Lessee, operating lease term				1 month												1 month
Minimum | Capitalized Software Development Costs
Significant Accounting Policies [Line Items]
Estimated useful life, years																3 years
Maximum
Significant Accounting Policies [Line Items]
Lessee, operating lease term				22 years												22 years
Lessee, operating lease renewal term				10 years												10 years
Finite-lived intangible asset amortization periods																40 years
Maximum | Trademarks
Significant Accounting Policies [Line Items]
Finite-lived intangible asset amortization periods																40 years
Maximum | Bakery Equipment
Significant Accounting Policies [Line Items]
Lessee, operating lease term				7 years												7 years
Maximum | Transportation Equipment
Significant Accounting Policies [Line Items]
Lessee, operating lease term				7 years												7 years
Maximum | IT Equipment
Significant Accounting Policies [Line Items]
Lessee, operating lease term				5 years												5 years
Maximum | Short Term Leases
Significant Accounting Policies [Line Items]
Lessee, operating lease term				12 months												12 months
Maximum | Capitalized Software Development Costs
Significant Accounting Policies [Line Items]
Estimated useful life, years																8 years
Direct Financing To Distributor | Maximum
Significant Accounting Policies [Line Items]
Notes receivable maturity period																10 years
Shipping costs
Significant Accounting Policies [Line Items]
Shipping costs																$ 1,063,600,000	$ 1,075,800,000	$ 1,010,500,000
Customer Concentration Risk | Outstanding Trade Receivables | Wal-Mart/Sam's Club
Significant Accounting Policies [Line Items]
Concentration risk percentage																19.80%	18.80%
Customer Concentration Risk | Total year to date sales | Top 10 Customers
Significant Accounting Policies [Line Items]
Concentration risk percentage																53.70%	53.60%	51.00%
Customer Concentration Risk | Total year to date sales | Wal-Mart/Sam's Club
Significant Accounting Policies [Line Items]
Concentration risk percentage																21.20%	21.20%	21.10%
Scan-Based Trading
Significant Accounting Policies [Line Items]
Sales																$ 2,200,000,000	$ 2,300,000,000	$ 1,900,000,000