Weighted average rate for present value of future retirement benefits cash flows, used to determine benefit obligation 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=108410482&loc=d3e1928-114920

Name:	us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Post-Retirement Health Care Post-Retirement Health Care (Valuation Assumptions) (Details) - Postretirement Health Coverage	Dec. 28, 2019	Dec. 30, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Discount rate		3.50%	4.00%
Scenario, Forecast
Defined Benefit Plan Disclosure [Line Items]
Discount rate	4.20%