Earnings Per Share (Narrative) (Details) - $ / shares shares in Millions	12 Months Ended
Dec. 31, 2020	Dec. 28, 2019	Dec. 29, 2018
Earnings Per Share [Abstract]
Antidilutive securities excluded from computation of earnings per share, amount	4.1	9.6	12.9
Antidilutive securities excluded from computation of earnings per share, exercise price, lower range limit	$ 52.32	$ 52.32	$ 50.04
Antidilutive securities excluded from computation of earnings per share, exercise price, upper range limit	$ 76.49	$ 75.83	$ 73.40

Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257

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No definition available.

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- Definition

The floor of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (g)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

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The ceiling of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.

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