Financial Instruments - Financial Liabilities Not Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Millions	Sep. 29, 2019	Dec. 31, 2018
Carrying Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt, excluding the current portion	$ 36,044	$ 32,909
Estimated Fair Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt, excluding the current portion	40,873	35,260
Estimated Fair Value [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt, excluding the current portion	$ 40,873	$ 35,260