Goodwill and Intangible Assets - Amortization expense (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
Dec. 29, 2018	Dec. 29, 2018	Dec. 30, 2017	Dec. 31, 2016
Impaired Intangible Assets
Total amortization expense		$ 66	$ 69	$ 66
Estimated amortization expense for 2019	$ 60	60
Estimated amortization expense for 2020	56	56
Estimated amortization expense for 2021	54	54
Estimated amortization expense for 2022	54	54
Estimated amortization expense for 2023	38	38
Asset impairment charges	38	$ 48	$ 47	$ 40
Patents and technology
Impaired Intangible Assets
Asset impairment charges	20
Trade names and trademarks
Impaired Intangible Assets
Asset impairment charges	$ 14

The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

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-Name Accounting Standards Codification
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Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill.

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Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the next fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the fourth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the third fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the second fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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