Postretirement Plans - Summary of Weighted-Average Discount Rates Used to Determine Postretirement Health Care Expenses (Detail)	12 Months Ended
Dec. 28, 2019	Dec. 29, 2018	Dec. 30, 2017
U.S. Postretirement Health Care Plans
Defined Benefit Plan Disclosure [Line Items]
Discount rate	4.20%	3.60%	4.10%

Weighted average rate for present value of future retirement benefits cash flows, used to determine net periodic benefit cost of defined benefit plan.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (k)(1)
-URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration