Income Taxes - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017	Dec. 30, 2017	Dec. 22, 2017
Income Tax Contingency [Line Items]
U.S. Federal Corporate Tax Rate prior to Tax Cuts and Jobs Act of 2017						35.00%
U.S. Federal Corporate Tax Rate after Tax Cuts and Jobs Act of 2017						21.00%
Effective income tax rate	15.00%	26.00%	14.00%	21.00%
Tax benefit attributable to discretionary pension contribution	$ 31
Employer discretionary contribution amount	250
Discrete tax benefit	44
Undistributed earnings of foreign subsidiaries	2,600		$ 2,600
Reductions Credited To Income Tax Expense		$ 38
Unrecognized tax benefits	57		57		$ 60
Unrecognized tax benefits that would affect the effective income tax rate	45		45
Tax-related interest and penalties accrual	25		25
Other current liabilities
Income Tax Contingency [Line Items]
Unrecognized tax benefits	8		8
Projected additions to unrecognized tax benefits	$ 6		$ 6