Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 29, 2019	Jun. 30, 2018	Jun. 29, 2019	Jun. 30, 2018	Dec. 29, 2018
Income Taxes
Effective income tax rate (as a percent)	22.20%	13.80%	19.30%	13.60%
U.S. federal statutory income tax rate (as a percent)		21.00%	21.00%	21.00%
Discrete tax benefit		$ 25	$ 12	$ 25
Unrecognized tax benefits	$ 175		$ 175		$ 141

Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

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Amount of increase (decrease) to previously recorded tax expense. Includes, but is not limited to, significant settlements of income tax disputes, and unusual tax positions or infrequent actions taken by the entity, including tax assessment reversal, and IRS tax settlement.

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Amount of unrecognized tax benefits.

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